20MM Ball Adapter Description: 20 mm attachment ball with dash mount arm. Function and benefits: provides a secure, adjustable mounting point on a vehicle dash for devices that use a 20 mm ball base. Compatibility: designed for 20 mm ball mounting interfaces. Practical applications: ideal for mounting GPS units, dash cams, or other accessories on car or RV dashboards. 17MM Ball Adapter Description: 17 mm ball adapter for mounting devices. Function and benefits: offers a stable 17 mm ball mounting option to position devices with ease. Compatibility: suitable for GPS devices, dash cams and some phone/tablet holders; supports Nuvi, Furrion Vision S 5' monitors, Garmin RV 795 GPS, and other 17 mm ball compatible mounts. Practical applications: mount a Nuvi or Garmin RV 795 on the dash; secure a Furrion Vision S 5' monitor in the vehicle; attach compatible phone/tablet holders. Use scenarios RV dash navigation: install the Garmin RV 795 GPS on the dash using the 17MM Ball Adapter for clear visibility while driving. Incabin display: secure the Furrion Vision S 5' monitor with the 17MM Ball Adapter for convenient viewing inside the vehicle. Dash cam or accessory mounting: attach a dash cam or other accessory that uses a 20 mm ball with the 20MM Ball Adapter for stable, adjustable positioning on the dash.