Garmin TM265LH Plastic Transom Mount Transducer, 1 kW, CHIRP, 12-Pin

Overview

The Garmin 010-12378-20 is a TM265LH plastic transom-mount transducer with depth and water temperature, using a 12-pin connection and 1 kW CHIRP low and high bands. It operates across 42 to 65 kHz and 130 to 210 kHz, with a maximum depth rating of 3,000 ft.

On the screen, the low band uses a wider beam for finding bottom in deeper water, while the high band tightens the beam to help separate targets around structure. Beamwidth ranges from 16° to 25° on the low band and 6° to 10° on the high band.

This model is built for transoms with 3° to 21° of angle, and the 39 ft cable gives you room to route from the stern up to the helm or an installed sonar module without extensions.

Key features

• 1 kW CHIRP Low and High coverage: 42 to 65 kHz and 130 to 210 kHz
• Maximum depth rating up to 3,000 ft for offshore and deep-water use
• Beamwidth options: 16° to 25° (low) and 6° to 10° (high) for wider search or tighter target separation
• Depth and water temperature sensing; no speed sensor in this model
• 12-pin plug for compatible Garmin sonar-capable displays and sounder modules
• Supported transom angles: 3° to 21°
• 39 ft cable for practical routing on center consoles, pilothouse boats, and larger rigs

Compatibility and fit

This is a transom-mount CHIRP depth transducer, so it needs a compatible Garmin sonar system that supports a 12-pin transducer connection and 1 kW CHIRP operation. Before ordering, confirm your unit has the correct transducer port and sonar capability for a low/high CHIRP 1 kW transducer.

Transom-mount transducers work best when they can sit in clean water at speed. If your hull has steps, strakes, or heavy aeration near the mounting area, plan placement carefully so the face stays in solid water when the boat is running and turning.

Installation and setup

Mounting position matters more than anything else. Place the transducer where it will see smooth water flow, keep it clear of the propeller swing radius, and leave enough space above the bracket for it to release and kick up if it strikes an object. A small adjustment up or down can make a big difference in bottom tracking at speed.

Route the cable well above standing water in the bilge, support it to prevent vibration wear, and keep it away from sharp edges and high-heat areas. Avoid cutting or splicing the transducer cable; if a splice is unavoidable, use a purpose-built watertight junction method intended for transducer cables.

Use on board

This transducer is a solid match for boats that spend time in deeper water and want bottom detail that stays readable, while still having a tighter beam option for working structure and bait on the high band. It also fits well for crews that want reliable depth plus water temperature without adding a separate temp sensor.

Orders are processed within 2 business days, which includes verification, packing, and dispatch. Orders of $100 or more qualify for free shipping when eligible. For orders under $100, shipping costs are calculated at checkout based on destination, package weight, and selected service. International shipping is available for eligible products, and certain items may require additional handling, warehouse transfers, or may ship directly from the manufacturer, which can affect processing time.

Deliveries are handled by preferred carriers such as USPS, UPS, FedEx, DHL, and others depending on your location and selected service. Estimated delivery times are displayed at checkout and may vary due to customs processing, carrier delays, weather, postal disruptions, or other circumstances beyond our control. Once your order ships, you'll receive a confirmation email with tracking information. Tracking may take up to 24 hours to update on the carrier's website and is also available through your account when applicable.

We ship throughout the United States and to most international destinations for products eligible for international shipping. International orders may be subject to customs duties, taxes, brokerage charges, or other import fees, which are the customer's responsibility and are not included in the product or shipping price. PO Boxes are accepted only when shipping through USPS, and not all packages qualify for this option. If your order does not arrive within the estimated delivery window, please contact us at info@apollolighting.com or +1 (954) 375-0100 so we can assist with locating your package.

Learn more.

Returns may be requested within 30 days of receiving your order. Items must be unused, uninstalled, unaltered, and returned in their original packaging with all tags, packing materials, blank warranty cards, manuals, instructions, accessories, and included items. Certain products, including installed or used electronics, electrical components, lighting, consumables, custom or special-order items, cut-to-length products, safety equipment, and merchandise exposed to water or marine conditions, may not be eligible for return.

To request a return, sign in to your account and select the applicable order and items, and submit your request for review. Eligible unfulfilled items may also be submitted for cancellation within 1 hour of placing the order. Returns or cancellations are not considered approved until you receive confirmation from Apollo Lighting. Please do not ship or drop off merchandise before receiving return approval and instructions.

Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

After your return is received and inspected, approved refunds are issued to the original payment method and may take 5-7 business days to appear after processing. Original shipping and handling charges are nonrefundable, and the value of any included free items that are not returned may be deducted from the refund. Apollo Lighting does not charge a standard restocking fee on eligible returns. Returns that are incomplete, damaged, installed, used, altered, improperly packaged, or otherwise do not meet the eligibility requirements may be refused. We recommend using a trackable and appropriately insured shipping service for all customer-arranged returns.

For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

Learn more.

Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

Learn more.