ITEM NAME:225Pcs Seal O-Ring R22 R134A Air Conditioning O-Ring Rubber Washer Assortme A3B6 225Pcs Seal O-Ring R22 R134A Air.Quantity: 225pcs Purple rubber O-ring. 225pcs Sealing ring: (Quantity & Size). 1 Set Rubber O-Rings (225pcs). Hydrogenated Nitrile Butadiene Rubber (HNBR), also known as Highly Saturated Nitrile (HSN) is special class of nitrile rubber (NBR) and is for mission critical applications.