These fit on XC m12 batteries. (1) Plastic Battery Holder. Patent Pending Design . (2) Magnets.
Sts Auto Design STS-MW1812F Milwaukee M18 12.0 Forge
STS Auto Design MW12HO – Milwaukee M12 High Output 5.0 Magnetic Battery Cover
STS Auto Design M18 xc3/4/5/6.0ah MW18XC Battery Magnetic Cover
STS Auto Design SN144 – Magnetic Battery Cover for Snap-On 14.4V Tools
STS Auto Design DCB205 Dewalt 20V 5Ah Magnetic Battery Cover
STS Auto Design MT16 – Matco 16V Magnetic Battery Cover