[High toughness and Strength] Highly selective material, Product Material: Brass ,beautiful appearance, smooth surface, acid and alkali resistance, anti-corrosion resistance, strong texture performance. [Inner hexagonal, male thread] The whole can be screwed into the inner wire joint to achieve the effect of flush with the wall after installation. Note: Hexagonal wrench is required for installation. [Product Size-5pcs of each size] 1/8''-External Threaded diameter appr.9mm 1/4''-External Threaded diameter appr.12mm 3/8''-External Threaded diameter appr.16mm 1/2''-External Threaded diameter appr.20mm [Product use of the Hex Head Plug]: Belongs to a kind of mechanical fastener, the role is sealing. Used in water, gas, oil and other media; can be screwed into the entire inner wire joint. Package Included: 20pcs Internal Hex Thread Socket Pipe Plug-20pcs 1/8" 1/4" 3/8" 1/2" (5pcs of each size), Weight: 0.3417165061 Pounds, Manufacturer: 15090074