Adjustable Parallels|4 Pc Set 3/8″ – 1-5/16″&6 Pc Set 3/8″ – 2-1/4″&3/8″ – 1/2″&1/2″ – 11/16″&11/16″ – 15/16″&15/16″ – 1-5/16″&1-5/16″ – 1-3/4″&1-3/4″ – 2-1/4″

Consists of two precision ground pieces which slide smoothly on each other Locked into position by set screws Can be quickly inserted into openings and expanded to exact size, then measured with a micrometer Country of Origin: China Tolerance Info: 3/8″ 1/2″: 0.0005″ 1/2″ 11/16″: 0.0005″ 11/16″ 15/16″: 0.0007″ 15/16″ 1-5/16″: 0.0008″ 1-5/16″ 1-3/4″: 0.0009″ 1-3/4″ 2-1/4″: 0.0010″