I've just fitted one on a new Mk2 Rapid and it lines up quite well. I didn't get on with my first Viper Connect and sold it to a friend, who uses it to good effect in HFT mounted on an Airwolf Tactical. I bought the current one to fit on a Mk2 Verminator but couldn't get it mounted to my satisfaction. They don't seem to have caught on at my HFT club yet.