This product is designed to test the thin soft metal pipe. It uses HR15T hardness scale, to test the materials, including copper / brass / bronze tube / stainless steel / mild steel / aluminum tubes and other soft metal pipe. Minimum pipe diameter can reach Φ4.8mm, the minimum pipe wall thickness up to 0.2mm, width of 1 inch opening apparatus (25.4mm), which is the maximum allowable tube wall.