Pair of the Prometheus Flat Hop Tensioners. These are a replacement Hop Tensioner (also known as the hop-nub) for use with the Prometheus Straight (flat) hop rubbers. The pack includes two tensioners, a hard type and a soft type. Fit only with special Prometheus Flat HopUp buckings. Please note that these might need modification to work with some inner barrels and/or hop units to account for different lengths in hop-windows.