Grab a spare transducer mounting knob now! Don't let a lost or broken knob ruin a fishing trip! Options: Cost Effective - Less durable with zinc plated 60mm bolt that could corrode over time. Standard 60mm - OEM replacement made out of more durable material and a 60mm stainless steel bolt. Extra Long 70mm - More durable material and a 70mm stainless steel bolt. This is designed for those using cable protectors or aftermarket transducer mounts where the stock mounting knob is too short. 20mm Perspective - This knob is made out of durable material with a stainless bolt and meant to replace the smaller knob that comes with the Garmin® Perspective Mount (see photo). This bolt is only used to mount the perspective mount to the transducer mount. It will not work to mount the LVS34 transducer itself. Sold as a single knob. Add on a second knob as a backup and save 10% or make it three and save 15%! Garmin is a registered trademarks of Garmin LTD. and in no way affiliated with this website or its products.