This screw-type anchor is the industry standard for pool safety covers. It fits all major manufactures of winter safety covers. All anchors will lay flush with your deck when not in use. These anchors are solid brass.
Installation requires 3/4 inch or 7/8 inch masonry drill bit. Anchor can be installed in most previously drilled safety cover anchor holes. The threads of these anchors may not match all existing anchor shells so you may need to replace the whole anchor.