One pair of adjustable (vernier) camshaft pulleys to suit all Lotus HC engined cars – Excel SE & SA, Esprit HC, SE, S4, S4s and GT3. These can also be used to upgrade from the early trapezoidal (square tooth) belts used on the Jensen Healey, Elite, Eclat and Talbot Sunbeam Lotus to the new more reliable HTD (round tooth) belt. The HTD belt does not slip like the early belts can do and the belt replacement interval is doubled. Unlike most of the vernier pulleys available for these engines, these pulleys have hard anodised teeth for improved wear resistance, they are CNC machined from billet aircraft grade aluminium. Six fixing bolts for extra security.