3M™ Dual Lock™ Reclosable Fastener SJ3460, Clear, 1/2 in x 50 yd, Type 250, 4 Roll/Case. 3M™ Dual Lock™ Reclosable Fastener SJ3460 is the easy and clear alternative to traditional fastening methods, such as screws, nuts or bolts. It is designed to deliver a durable, reclosable fastening solution, which can be opened and closed multiple times. This fastener is most commonly attached by applying hot melt, epoxy or liquid adhesive.