Designed for measuring depth of holes, slots and recesses. Highly accurate with fine adjustment, for use in toolrooms and inspection departments on jig, fixture or die work. Maximum accuracy and easy adjustments are insured by tight, smoothly fitted vernier scales. Clear .001" or 0.02mm graduations on satin-chrome finish. Hardened stainless steel. All bases are hardened and micro-lapped. 4" standard base size. Wider extension bases. Complete with fitted carrying case.