These are HellermannTyton Insulok T50L cable ties in black, sold as a pack of 100. The T50L is a long, medium-width tie from HellermannTyton's standard T-Series: about 390 mm long (the supplier lists 392 mm) and 4.6-4.7 mm wide, with inside serrations and a one-piece plastic pawl that locks as the strap is drawn through the head. It bundles from about 1.5 mm up to 110 mm diameter, so a single length handles anything from a few signal leads to a thick loom, and HellermannTyton quotes a minimum tensile strength of 225 N for the black PA66 version. Typical uses are dressing cable runs in racks, flight cases and stage trunking, bundling speaker, microphone and DMX looms, and general installation work. The ties are halogen-free polyamide 6.6 (UL 94 V2), rated for -40 to +85 degrees C; HellermannTyton notes the standard black version is not UV stabilised, so long-term outdoor exposure is not recommended. The bent tail makes hand application quick, and they can also be fitted with HellermannTyton tensioning tools. These are single-use, non-releasable ties.