This is a pair of the much-sought-after Prometheus Flat Hop Tensioners (Bridge type). 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 - We recommend trying both to see what gives you the best results.
While these are designed and should work best with the intended Prometheus Straight hop rubbers, they should work with just about any hop rubber as long as it is the mound-less (straight) type, or if you remove the mound from a conventional rubber.
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.