Features 1、Clear and Easy to Read: Our gauge inside caliper pointer readings are clear and easy to read, with longer life and high accuracy to help you minimize measurement errors. 2、Specifications and Measuring Depth: Gauge inside caliper is available in 55‑153mm or 2.2‑6in with a reading of 0.01mm and a measuring depth of 90mm or 3.5in. 3、10 Replacement Heads: The gauge inside internal caliper kit contains ten interchangeable internal caliper heads with different ranges and specifications for you to use according to the actual situation. 4、Aluminum Material: Gauge inside caliper is made of aluminum alloy material with exquisite craftsmanship, wear resistant and practical, which can be used stably. 5、Widely Used: Our inside caliper is widely used for the measurement of all kinds of bore, inside diameter, inside groove size. Specification Item Type: Gauge Internal Caliper Material: Aluminum Alloy Specification: Approx. 55-153mm/2.2-6in Reading Value: 0.01mm Error: ±0.02mm Measuring Depth: Approx. 90mm/3.5in Use: Widely used in all kinds of internal holes, internal diameter, internal groove size measurement Package List 1 x Gauge Dial Inside Caliper 2 x Wrench 10 x Gauge Dial Inside Caliper Head 1 x Manual 1 x Storage Box