The Fowler 52-565-700-0 turns most 6" and 8" vernier calipers into a depth gage instantly. Easily attaches to the beam of your caliper with one screw. A 3" base allows sturdy depth measurements. Precision and hardened surfaces. This product has a 1 year warranty offered by Fowler High Precision. If you experience any problem contact Fowler directly for warranty claims. Fowler, an American company, manufactures inspection and measurement instruments such as electronic indicators, calipers, bore gages and digital scales. The company founded in 1946, is headquartered in Newton, MA.