One of those things you wonder how you lived without. They are an aluminum tube wrapped with a thin rubber. You unscrew one piece from the other to get 2 line tensioners that are SUPER handy for tying knots by wrapping the line around the non slip handles. You can use the open end for pulling hooks and they are essential if you tie PR knots, FG knots or even pulling a snagged hook from the bottom. Made of aluminum so they never rust. A tool that will last for years or until your buddy steals it from you! Choose your color from the menu.
 
Picured is 2 units- one together and one unscrewed. You are buying 1 unit which unscrews to the 2 pictured pieces.