Fits all GM based LS engines. Make LS Harmonic Balancer installation easier and time saving for you. Easy to use, Simply thread the tool into the crankshaft until it seats, then tighten the nut down until the pulley is seated. At Royalo,We Aiming to give our customers the best products and services.If you are not satisfied, refund 30 days unconditionally. 3 years warranty