It is necessary to hold the flywheel in a secure position while servicing the balancer retaining bolt. The ST-94 provides for damage free securing of the flywheel utilizing the access hole in the bellhousing and reducing the likelihood of case damage. You'll find Stallion Products are widely considered the most heavy duty on the market! This is a high-quality tool and you will be pleased with your purchase. Don't try to save a few bucks at the expense of your engine - know that you're getting quality from Stallion Products.