Tourna Quasi-Gut Armour 16 Tennis String Packages : Tennis players looking for strings that are easy on the arms and loaded with power should strongly consider the Tourna Quasi Gut Armor(TM). These strings take the orginial Quasi Gut and adds two ribbons of co-polyster to increase durability. This creates a comfortable, firm responsive with impressive control on the court. Good for players who... Are prone to tennis elbow pain and need softer strings. Are looking for a comfortable yet durable multi-filament that can be hybrid with co-poly. Enjoy the soft, arm-friendly feel of multi-filaments but tend to break strings often.