Brass Calipers (Inside and Outside) **Used for making both internal and external measurements. **External measurements can be made from 0 – 4 (0 – 100mm) whereas internal measurements can be made from 7/32 (5mm) to 4 (100mm) A handy pocket caliper made from solid brass. Close tolerance dovetail design ensures smooth motion of the caliper and provides accurate measurements. Graduated in both imperial and metric graduations with a least count of 1/16 on the imperial scale and 0.1mm on the metric scale Ideal for use by mechanics hobby crafters etc. who need to take measurements on small objects such as nails screws lenses tubing etc.