The Stellarvue TP10 Dovetail Rail measures 7 7/8" long and is a Vixen-style. It is used to attach mounting rings or plates to Stellarvue M1 and M3 mounts, Vixen mounts, CG5, EQ5, GP, LXD55 and other compatible mounts. In addition, the Stellarvue TP10 Dovetail Rail utilizes a 1/4 - 20 standard for use with a camera tripod. Custom machined with side offsets for use with Vixen GP style safety screws. Stellarvue Product Number: TP010