I use the Dunlop Aerogel 300. Pro Supex Big Ace 17g at about 58 lbs in the Mains. For the crosses, I've been experimenting with different multi-filaments. I've used Volkl Fibre II and Babolat Xcel Premium so far, and have get it strung at 55 lbs. So far I like the Volkl the best. I think the next string I'll try for the crosses will be Technifibre NRG.