The RAP-274-1-GA5 consists of the EZ-ON/OFF™ dual strap base, swivel diamond adapter base and high strength composite cradle for Garmin eTrex (Non-Color) GPS devices. Adjust the zip ties to attach to a variety of rails, from a minimum of 0.5" in diameter. With a press on the diamond adapter the EZ-ON/OFF™ system allows for the quick release of the Garmin eTrex cradle from the base. When connected, the diamond base can rotate, allowing for you to position the Garmin eTrex cradle for optimum viewing.