Lets you use AA CWBP battery box with ECOTI/ECOTI2/ECOSI with your PVS31A or similar goggle system using the fischer 4 pin connector. Works perfect. I use one to power my ecoti by itself with 2x AA battery instead of expensive CR123a. Or use the BNVD cable by itself without the ecoti connector or both together!. Have a couple of these cables, asking $180 shipped each OBO. US ONLY, US CITIZENS ONLY
