CASE SIZES: 1.5", 2", 2.5", 3.5", 4", 4.5", and 6", 8", 10",CASE MATERIAL: Steel case, steel ... Explanation:CASE SIZES: 1.5", 2", 2.5", 3.5", 4", 4.5", and 6", 8", 10", CASE MATERIAL: Steel case, steel ... , steel chrome plated case TUBE& SOCKET: Brass, stainless steel, steel with nickel plated, 316 stainless steel,phosphor bronze and so on ... lens are available ACCURACY:1.0,1.6,2.5,4.0 gas pressure gauge