Sandseal power pulley, small, with seal Type 1Sandseal pulleys are available in standard or in a smaller diameter. The kit consists of a seal in a holder, which is to be placed in the engine case and the pulley has been specially adapted to be assembled into this holder. The advantage is that fine substance can be kept out of the engine (f. i. when off road) as well as that engines with under pressure wont be able to throw their oil outside through this way.