This Vernier Caliper is for inside and outside measurement in metric or English units. It is ideal for learning precision measurement techniques by using the vernier principle. Additional Description The Vernier Caliper is dual scale and the metric scale measures a maximum of 12.5 cm in 1 mm increments and the 10 part vernier reads to 0.1 mm. The English scale is graduated to 5 in in 1/16 in divisions and the 8 part vernier reads to 1/128 in. This caliper also features a locking pin to secure readings and a knurled thumbwheel permits fast and easy measuring. Its beveled cross horns are useful for internal measurements. The Vernier Caliper is made of plated steel and come packed in a plastic case for safe storage.