These are HellermannTyton Insulok T120R heavy-duty cable ties in black, supplied here in a pack of 50. The T120R is one of the wider ties in HellermannTyton's standard T-Series: about 387-390 mm long and 7.6 mm wide (the supplier lists it as 390 x 7.8 mm), with inside serrations and a one-piece plastic pawl that locks the strap as it is pulled through the head. It bundles from about 3 mm up to 100 mm diameter and HellermannTyton quotes a minimum tensile strength of 535 N for the black PA66 version, so it is suited to heavier looms such as multicore and speaker cable runs, power cables in racks and stage trunking, or securing hoses and conduit. The material is halogen-free polyamide 6.6 (UL 94 V2), rated for -40 to +85 degrees C, and HellermannTyton notes the standard black version is not UV stabilised, so it is best used indoors or out of direct sunlight long-term. The ergonomic bent tail makes hand application quick, and the ties can also be fitted with HellermannTyton tensioning tools. These are single-use, non-releasable ties.