Velcro Strip Size Velcro (width) 1/4" (6.35mm) Velcro (width) 3/8" (9.5mm) Velcro (width) 1/2" (12.7mm) Velcro (width) 3/4" (19mm) Velcro is sold by the foot (305mm). Ever wonder how to properly fasten your battery packs? Always put Self adhesive Velcro on the battery (loop side) and Self adhesive Velcro (hook side) on battery tray. We use small pieces on both sides of the pack. This way battery pack ones tightened cannot move and cause any damage. For .60 size planes we use 1/2" Velcro strip around the packs and battery tray.