uxcell 1/4BSP Adjustable Pneumatic Muffler Silencer Air Flow Control 4pcs Product Name : Pneumatic Muffler;Male Thread Diameter : 12mm/ 1/4BSP Overall Size(Approx) : 42x13mm/1.7"x0.5"(L*Max.W);Material : Brass Main Color : Brass Tone Net Weight : 89g Package Content : 4 Pcs x Pneumatic Muffler