Well, what else would you call them?!?
These steel contraptions are filled with leaf hops then are placed into our conditioning tanks for a week to allow the lovely lupulins to infuse into the beer much in the same way a teabag works... if you had a six-foot stainless steel one.
We've long wanted something to allow us to dry hop with leaf hops in the conditioning tanks; we measure the T90 pellets directly into the tanks but leaf hops block up the outlets and just about everything else so, after various experiments with muslin bags and suchlike, we've had these made by our friends at AJP stainless in Hereford, home of the Wobbly brewery, especially for our 700 litre tanks.
We've not tested them in anger yet but they should work a treat; we'll let you know which beer has used them so you can judge their effectiveness for yourself!