3D printed TPU 95 rubberized plug shaped to fit into the external battery plug port on night vision devices with the 4 pin LEMO connections ( compatible with: AB Nightvision RNVG, RPNVG, RNVG-A, ANVIS 6-9, and legacy Nocturn Industries Katana and Daisho and other devices that have a 4-pin LEMO port ) and 4 pin Fischer connections ( compatible with: L3 Cold Weather Battery Pack, Argus USBP, and other battery packs with Fischer style connections.) Made to prevent damage/ingress of debris into the fragile battery port. Protect your investment.
