This is a SINGLE 11.11 x 1.78 Nitril O ring for the pump cylinders for the ALTO Speed 4050 X-TRA Cold Water Pressure Washer.
Please Note: They are sold EACH you are paying for ONE "O" ring.
It will probably suit other similar Nilfisk-ALTO models of domestic pressure washers.
See the consumer accessory book HERE
At the moment standard postage within Australia, is capped at a maximum of $20!