Like all GFB lightweight pulleys, this one begins life as a single 6061 T6 aluminium alloy billet, and is then precision CNC machined to exacting tolerances. GFB then anodizes it black for a stealthy appearance and superior wear resistance.This results in a large saving of 4.87 lbs. of rotating mass over the factory pulleys, without sacrificing strength or reliability. Like all GFB lightweight pulleys, you can feel the improvements:* Sharper throttle response.* Crisper acceleration through each gear.* Retains the use of OE.Weight Comparison Between Stock and the GFB Lightweight Pulley.* Factory Crank Pulley - 4.89 lbs.* GFB Crank Pulley - 0.75 lbs.* Factory Water Pump Pulley - 1 lb.* GFB Water Pump Pulley - 0.53 lb.* Factory Alternator Pulley - 0.44 lb.* GFB Alternator Pulley - 0.18 lb.* Weight Savings vs. Stock = 4.87 lbs.!