The 71-6450 Adjustable Target Set for Small Bores is used to center your target in bores from 5-1/2" to 21-1/2". This is a complete set with 3 sets of legs and all I.D. Micrometers. This will accomodate all A.I.A. Standard 2-1/4" targets. and come in its original factory mahogany box.