Boshart Industries fast recovery heat shrink kits are made of adhesive lined cross-linked polyolefin heat shrinkable tubing that is designed for applications up to 600 V. The good abrasion resistance characteristics of this tubing provide excellent mechanical protection. When heated above 120 deg C (250 deg F) there is a 4:1 shrink ratio. Upon cooling the adhesive solidifies, forming a permanent, non-drying flexible and waterproof barrier. Black tubing is flame retardant, clear tubing is not flame retardant. Boshart Industries Heat Shrink Kit, Lead Free Fast Recovery, Specifications: 0.45 in ID Expanded, 0.102 in ID Recovered, 3 in L Tube, 0.043 in THK Wall, 2 Piece, Polyolefin, Black