The shrink wrap is for covering your custom battery packs as well as other products For the best result use Hot Air but if there is not Hot Air available you can use a hair dryer to evenly heat up the wrap to shrink until it is tightly wrapped around the battery pack. It's 0.1mm thick with . 2:1 shrink ratio. Shrinking rate: section: 48% +/-5; longitudinal: 15% +/-3 Shrinking temperature: 80 Celsius black Flame Retardant Length:2m Flattening Width: 120mm (diameter of about 76.39mm) Colour:black Material:PVC Package Contents: 3 x Heat Shrinkable Battery Cover Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.