The Mitutoyo 2977TB Standard One Revolution Type Series 2 Dial Indicator is for error-free reading. Features a unique Shock proof mechanism providing improved immunity to shock due to sudden spindle retraction caused by high impact. The crystal is hard coated for durability and scratch resistance and is also about 40% lighter than the conventional dial indicator. Provided with improved resistance to shop floor contaminants such as water and dust. Due to the spindle bushing being offset from the stem, spindle movement will not be hindered or jammed when clamping along the stem. Includes a pair of limit hands for quick and easy GO/±NG tolerance judgment. This model has a Flat Back with a range of .04" and .055" full stroke, .0005" graduation and 20-0-20 Dial Reading with a 3/8" Stem.