With the increasing use of serpentine drive belts on late model engines, more Nuline idler and tensioner pulleys are being sold than ever before. All Nuline engine pulleys incorporate ball bearings that run at very high revs relative to engine speed. Increasing belt load and exposure to dirt or moisture accelerates bearing wear. All ball bearings used are from OEM manufacturers and feature C3 rated high speed races, high temperature lubricant and heavy duty silicone seals for maximum service life at high RPM's. Nuline pulleys are the number one choice for Australian vehicle repairers.