The Autofill Valve Tool is for use with PoolMiser autofills only. There are 4 holes located in the top of the tool to insert a screw driver for tightening or loosening of the autofill valve stem easily with minimal effort. This tool is made out of durable 304 stainless steel. This tool makes it easy to install PoolMiser pool autofills or replace the auto fill o-rings quick and easy.