The RAP-274-1-GA31U consists of the EZ-ON/OFF™ dual strap base, swivel diamond adapter base and high strength composite cradle. 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 nuvi cradle from the base. When connected, the diamond base can rotate, allowing for you to position the Garmin nuvi cradle for optimum viewing. This mount includes a 12 degree tappered shaft for tapered handlebars.