Plastic muffler is great for pneumatic equipments use. With male thread, easy for you to fix and take it off. Attached to pneumatic exhaust port to diminish noise. Product Name : Pneumatic Silencer Muffler;Male Thread Diameter : 21mm/ 1/2 quot; PT Overall Size : 101 x 43mm/4 quot; x 1.7 quot;(L*Max.D);Material : Plastic Main Color : White, Black Net Weight : 28g Package Content : 1 x Pneumatic Silencer Muffler