还位内卡钳(附图)由活动量爪和固定量爪所组成。活动量爪靠杠杆(滑槽板)与定位卡钳板连结,并由钩爪控制其定位或脱位。该卡钳除增加了部分小附件外,其它与一般内卡钳相同。它具有结构灵巧、使用方便、测量准确的特点,解决了因孔径中间大两端小不易测量的困难。 Also inside the calipers (with photos) by the activities of claws and fixed amount of claws. The amount of activity claws lever (slide plate) and the positioning caliper plate connection, and by the claw control positioning or dislocation. In addition to the addition of some of the small caliper accessories, the other with the same general calipers. The utility model has the advantages of dexterous structure, convenient use and accurate measurement, and solves the problem that the small ends in the middle of the aperture are difficult to measure.