Fielect 20Pcs 21700 Lithium Ion Cell Double Battery Holder Bracket for DIY Battery Pack 21_7mm Hole Dia

Crack resistant edge with the slot, with the firm, It can accomodate various size. It can withstand high drop, high strength support, easy to heat dissipation, convenient combination, fixed specifications, and free combination. With professional battery holder to replace the traditional general adhesive, which would brings convenient combination and more firm connection, as well as brings convenient maintenance of the battery.its the best choice of the battery combination.