This fiddle block kit is an ideal accessory to the Portawrap that allows the user to pretension lines, create lift or simply remove slack from systems with lots of rope in between. Fiddle blocks provide a very compact, in-line system for incredible 5:1 mechanical advantage resulting in 1,000 lbs. of lifting or pulling power from only 200 lbs. of input into the system. Steel carabiners and prusik are for attaching blocks to line and anchorage.