Gamma Pro Squash String comes in 17 gauge only. Gamma, a leader in the tennis string market has now launched 3 new squash strings for 2011. The Pro Squash string is a premium multifilament featuring Gamma's Livewire technology. This is a perfect string for the all levels of squash play. The Pro Squash string is the stiffest of the 3 new Gamma strings, constructed of larger core fibers to limit flex of the string bed. This feature improves control by limited the amount of string/ball contact during strike. Color: Black.