A very accurate low cost caliper. Accurate enough for professional use. One of the most widely used professional calipers in the world. Easy to use with convenient palm grip and trigger. Made of durable plastic material. Accepts large skinfolds: 80 mm+. Comes with manual entitled, "How To Measure Your % Body Fat" by W.C. Donoghue. Manual offers comprehensive instruction and norm charts. Lifetime warranty through manufacturer.