Protect your fiber optic splices with these precision-engineered fusion sleeves. Each 2.5mm x 40mm sleeve combines a transparent heat-shrink outer tube with hot-melt adhesive and a reinforcement rod for superior alignment and durability. The clear design enables visual inspection of your splice quality before and after heat treatment. Pre-shrunk configuration minimizes installation errors while maintaining compatibility with standard fusion splicer ovens. Achieves full recovery in approximately 90 seconds with excellent thermal and environmental resistance. This 400-pack delivers reliable performance for professional fiber network installations and repairs.