Lee 10MM AUTO Case Length Gauge is a precise, easy way to trim to length and square the case mouth. Used with the Cutter and Lock Stud or Zip Trim. Trim to length .982 to .992 inches. Size 10mm Type Case Length Gauge w/Shell Holder Finish Silver Series with Shell Holder Weight 0.06 lbs Caliber 10mm Auto Function Measure Cases Includes Shell Holder Material Steel Quantity 2 Piece Media Type Brass Shell Compatible With Cutter/Lock Stud