The Universal Slide Rapit Extension provides a fast method for extending the length of a rapit spring end Bearing 2’’ to accomodate insulation on wrapped duct. There is no need for tools; just twist the extension fork over the threaded bearing and slip the sleeve over the joint. The new body design, with an added recessed stainless steel slide pin, makes installation fast & easy.The durable, heavy duty die cast housing and slide core make this the toughest bearing extension in the industry. The knurled ends create a non-slip grip on the bearing, for the best blade anchoring and no slippage at higher CFM applications.