Silicone bypass hose that can be removed and reused many times. These seem to last forever! After a series of failures caused by poor quality rubber hoses, particularly the concertina type pipes which seem to perish after only a few months, we switched to these silicone hoses. The water pump will need to be removed to fit this hose to a built up engine but the advantage is you will never need to worry about changing it again. Supplied with a pair of hose clamps to suit