K-D Tools 2991 3-3/4""End Cap Oil Flt Wr" Square drive end cap oil filter wrench for 3-3/4 inches diameter filters It is designed for use with a 3/8 inches square drive tool or a 1 inches wrench Tool is zinc plated to resist rust Be sure fluted end of filter matches wrench Wrench measures 3/8 inches in size and removes and installs filters