1" x 150' Black (1 Pack) 3M SJ3541 Dual Lock™ Fasteners. Fastens heavy items creating a more permanent bond. Rigid plastic stems interlock for hundreds of closures. Rubber based adhesive on back of a polypropylene, reclosable fastener. Type 400 stem density mates to types 170 or 250 but not to itself. 150 feet of usable product. Does not interlock with itself. Designed to bond to many plastics, powder coated paints and other low surface energy materials. Indoor use in temperatures up to 120 degrees F. Stems interlock with DK3M122 or DK3M127.