The Pulsar® 71749 .25" -20 x 3.25" 4-Pack PVC ESV Screw for Pulsar® 4 System is a set of screws intended to repair or replace the original installation screws from the Pulsar® 4 pool maintenance system. This four pack of screws is durable and made to help restore your system to full functionality in the event of damage or malfunction. For best results, always refer to manufacturer directions for repairing, replacing, or adding components to pool maintenance systems.