?lifetime warranty?Bolt head adapter ball base is an on-board accessory designed for bikes, motorcycles and cars, you can give this phone holder base along with other phone mount accessories as Christmas gift to your husband, father, son or friend, give them the surprise and fun of assembling mount. This bolt head adapter ball base offers lifetime warranty, if there is any problem, please feel free to contact us, we will provide you the best solution within 24h. ?Quality First?This bolt head adapter ball base body is made of 6061-T6 aluminum alloy, CNC integral molding structure is strong, surface treated with Class III hard anodized finish with high durability, TPU covered ball head is non-slip wear-resistant and not easy to loosen, can withstand large weight and impact, It's best choice for assembling bicycle cell phone holder, motorcycle cell phone mount, scooter phone holder, baby stroller phone holder and other phone mount base. ?Easy to install?This 1-inch ball head adapter with 10mm mounting holes provides a solid connection between the mounting base and the double socket arm, with a ball head diameter of 25.4mm, which can be easily installed on the motorcycle mirror frame and bolt head without tools, easy to operate in just a few steps to complete the installation, weighing only 41 grams, exquisite and compact for easy portability and use anytime, anywhere. ?Quality Details?This rearview mirror U-bolt base comes with short screws *2 (support installation diameter 10-13mm) and long screws *2 (support installation 10-16mm), short screw thread length is 12.5mm, long screw thread length is 18mm, you can choose the suitable screw style for your rearview mirror U-bolt base according to the use requirements, complimentary screw wrench to easily complete the installation work?. ?Wide compatibility?Bolt head adapter ball base compatible with RAM mount and FANAUE any B size 1 inch ball head double socket arm, ball and socket technology allows near infinite adjustability,suitable for other devices with 1 inch swivel ball mounting pattern, provides reliable support for your motorcycles bike phone mount, can be mounted on scooter/stroller/motorcycle/bike/motocross bike etc. on anything with 10MM screw holes equipment.