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.

Shipping
We ship worldwide from the United States. Rates are calculated at checkout based on destination and package weight. Some items include free shipping, which will show automatically. Not every product is eligible for international shipping; checkout will confirm eligibility. We do not ship to PO Boxes except through USPS, and not all packages qualify.

Processing and dispatch
Most orders are verified, packed, and handed to the carrier within 1 to 2 business days. Some products may need extra handling time or ship directly from the manufacturer. For certain international orders, inventory transfers between warehouses may add time. If any delay is expected, we will let you know the dispatch date.

Delivery and tracking
Deliveries are handled by trusted carriers such as USPS, UPS, FedEx, and DHL. Estimated arrival times appear at checkout and depend on your location and the service you choose. These are estimates and can be affected by customs or carrier disruptions. A shipping confirmation with a tracking link is emailed when your order ships, and tracking may take up to 24 hours to update. You can also view tracking in your account.

Duties, taxes, and support
International customers are responsible for any customs duties, taxes, and fees charged by the destination country. If these charges are refused and a shipment returns to us, the carrier’s return cost and any re-entry customs fees will be deducted from the refund. If your order is late or you need help, contact cs@qualityboatparts.com and we will assist you.

Quality Boat Parts is a reseller. Many items include a manufacturer’s warranty, and all warranty service is handled directly by the manufacturer. We do not manage or administer warranty claims on behalf of customers.

Warranty terms, coverage, and duration are set by each manufacturer. Issues involving defects, repairs, or replacements must be addressed with the manufacturer’s support team. When available, the warranty period is listed on the product page. If it is not shown, contact us or the manufacturer for details before purchasing.

To start a claim, the customer must contact the manufacturer and follow their process. Keep your proof of purchase and original packaging, and register the product if the manufacturer requires it, as these are often needed for warranty service.

We are happy to help you find the right contact or documentation, but we cannot decide outcomes or intervene in claim resolutions. For guidance, email cs@qualityboatparts.com.