CASE SIZES: 1.5", 2", 2.5", 3.5", 4", 4.5", and 6", 8", 10", ... , steel chrome plate case Product Explanation:CASE SIZES: 1.5", 2", 2.5", 3.5", 4", 4.5", and 6", 8", 10 ... so on. Element: Brass, CONNECTION:1/8", 1/4", 1/2", 3/8", NPT,BSP or BSPT dependent on model& size ... , glass& polycarbonate lens are available ACCURACY:1.0,1.6,2.5,4.0 gas pressure gauge