This coupling is expensive compared to a standard coupling because of production/sales volume. Ordinary couplings, sold in mass quantities, have a stop inside to assure that the pipe is inserted to the perfect depth. That works fine if the ends of the pipe can be separated at least 3" and can be inserted into the fitting. This REPAIR fitting has no stop, and is used ONLY when the pipes being connected are fixed in place and have little linear movement. As long as one pipe can be shifted enough to get the fitting over it, the fitting is dry installed over one pipe and slid out of the way of the splice point. Mark each pipe to assure you can judge when the coupling is centered, apply glue to both pipe ends and then slide the coupling over the splice, taking care to center the coupling across the splice.