Comparison : Item # W5108-2, 1/8" Thread Size Compliant Domestic Cast Red Brass Cap
Item # W5108-4, 1/4" Thread Size Compliant Domestic Cast Red Brass Cap
Item # W5108-6, 3/8" Thread Size Compliant Domestic Cast Red Brass Cap
Item # W5108-8, 1/2" Thread Size Compliant Domestic Cast Red Brass Cap
Item # W5108-12, 3/4" Thread Size Compliant Domestic Cast Red Brass Cap