Replacement 15" Allen Wrench for In-Ground Safety Covers. Allen wrench used for safety cover anchors to raise and lower the anchors according to season. Long arm wrenches provide extra reach and greater torque. A great tool for your pool maintenance supply. Made By Loop-Loc Replacement 15" Allen Wrench for In-Ground Safety Covers. Allen wrench used for safety cover anchors to raise and lower the anchors according to season. Made By Loop-Loc