Based on this product's specifications, here are some alternatives and similar models
Heat shrink tube HellermannTyton 323-20400, black, 1 m length, dia 4–12 mm, pack of 15
Summary description:
HellermannTyton 323-20400 is a black heat shrink tube supplied in 1 m lengths, pack of 15 pieces. The tube covers nominal diameters from 4 mm to 12 mm (minimum/maximum diameters listed) and is intended for insulating and protecting cable joints, harnesses and connectors. Suitable for electrical insulation, strain relief and environmental protection in wiring and repair tasks.