4. Aluminum Material: Gauge inside caliper is made of aluminum alloy material with exquisite craftsmanship, wear and practical, which can be used stably. 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. 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. 3. 10 Replacement Heads: The gauge inside internal caliper kit contains ten interchangeable internal caliper heads with different ranges and specifications to use according to the actual situation. 5. Widely Used: Our inside caliper is widely used for the measurement of all kinds of bore, inside diameter, inside groove size., Weight: 1.33930824165 pounds, Manufacturer: NONDK