3M Dual Lock Reclosable Fastener TB3870 250/250 Black, 1 in x 10 ft, 2 strips Type 250 stem density polyolefin fastener which mates to Type 170, 250 or 400. Designed to bond to many plastics and powder coated paints and medium to low surface energy materials with little or no surface preparation. General Industrial, Transportation, Speciality Vehicle, Medical, Military, Packaging, Point of Purchase Displays, Exhibits, Electronics, Construction, Furniture, Maintenance Repair and Operations (MRO) Attach Doors, Flexible Solar Panels, Headliners, Access Panels, Signs and Display Components. There are Two different strips that interlock in a bag but only One Mated Strip in a bag.