!NEW! Fish Paper Insulation Rings for 18650 Cells, Sheet of 20

These are 18mm OD x 10.5mm ID fish paper insulation rings, used for protecting the positive terminal of 18650 sized cells from the heat and abrasion of spot welding. They protect against short circuits caused by the heat of spot welded tabs melting through the cells plastic insulation layers, as well as prevent sharp edges of tabs from cutting through. They are an essential part of any pack build.