I first bought some Busch & Muller Cycle Star mirrors but they vibrated a lot and were easily put out of adjustment and didnt seem like they would last very long. The Mirrycles are rock solid and because the adjustments are not on balls and sockets are easier to move out of the way when needed and then quickly back into focus. Adjusting the focus of the mirror by rotating on a bolt in each dimension means they are far less likely towear out like a ball and socket. And the tension is easily adjusted by tightening or losening each of the three allen head bolts. Melbourne Powered’s prices are good and delivery is quick. Highly recommended. It’s 3 out of 3 dimensions from me!!!