Our Aluminum Bar Tensioners are the best working, simplest to use, line tensioners made. They will immediately replace any line tensioner you are currently using as they are extremely lightweight and hold like nothing you've ever seen. We designed the tensioners to work with all 2-3mm lines. To rig the tensioner, thread the end of the line through one hole, back through the other hole and then tie a knot. To tension the line you pull the tensioner which bites down when you stop pulling. To un-tension the line you twist the tensioner and it unlocks its grip. They are made from Aerospace Grade 6061-T6 Aluminum and tumbled until they are silky smooth. Like all of our products these are proudly manufactured by us right here in the USA. Weight is 3 grams each (10=1oz). Size is .25"x.25"x1.30".