The Samsung Galaxy S3 will fit in the X-Grip cradle, either the RAM-HOL-UN7U (snap-link version), or the RAM-HOL-UN7BU (with 1" RAM ball). The rubber washer comes with the UN7 snap link cradle, and is designed to fit into the socket before the snap-link ball is inserted. It helps to increase the friction between ball and socket and keep it sturdy.
After viewing video watch?v=K2G3FamLAuQ what do you think caused the mobile to fly away? And what could have been done to prevent this situation from happening?
mozbius This is speculation, but it looks to me like the person in that video was using the RAM-HOL-UN10BU, which is a slightly larger version of the X-Grip designed for larger phones, like the Note 2. The UN7 is the more common X-Grip, and because it is smaller, is going to grip devices a little tighter.
GPSCity That could explain it. I'm still going to order this and think of a failsafe (some kind of a leash perhaps or locking mecanism) and test the Xgrip in one of the most demanding roads in the civilised world... Montreal, Quebec! :-)