EXPANDABLE SLEEVE/Black, flame retardant, 1/2" diameter. Expandable sleeving is light weight, self-fitting, polyester, mono-filament sleeving designed to encapsulate and protect cable bundles and wire assemblies. It adjusts to irregular surfaces and contours providing abrasion resistance and protection with a minimum of bulk weight. Flame retardant sleeves designated by numbers that have "XPF".