These are retractable Swimming pool safety cover brass anchors designed for use with inground swimming pools. The top of the anchor has an ocatgon Allen head hole for screwing the anchors into and out as they are needed. This type of anchoring system is used on tarps or covers to give the cover a trampoline effect. These inserts are not effected by pool chemicals.Ask us / Request quote for lead free fittings for portable drinking water use </br></br> Can be used as a replacement of Latham, Loop-Loc, Meyco, Rayner, Tara, Merlin, GLI and most major brand safety covers.