Comparison : Item # W118-2, 1/8" Thread Size Compliant Yellow Brass Recessed Hex Head Plug
Item # W118-4, 1/4" Thread Size Compliant Yellow Brass Recessed Hex Head Plug
Item # W118-6, 3/8" Thread Size Compliant Yellow Brass Recessed Hex Head Plug
Item # W118-8, 1/2" Thread Size Compliant Yellow Brass Recessed Hex Head Plug