I don't do 2 piece generally, did it first with Aerobite. Aerobite gives you 5.5m of red string for the mains, and 5m of aerosonic for the crosses. 5m for the crosses was plenty. I want to try a hybrid with BG80 and Li Ning No.1, and am buying 2 packs of each to test this. This is not off of a reel. All of the videos I've seen suggest, with a 10m length, adding some extra length to the mains and doing like 5.3m main and 4.7 cross. However, if I do it this way I'll have: 1 5.3m set of BG80 and 1 4.7m set, the 4.7m set would be.. useless to me. It wouldn't be long enough to do another set of mains. I'm stringing a normal head-size 76 hole, with a Penta Premium 3600 dropweight.