Kitty String is one of the most durable strings in the world by only using high class materials. Tips when using Kitty String: There is no finger loop on the end of the string. Please make sure to cut your Kitty string to your own preferred measurement and make a finger loop before play. Stretch your Kitty String before using it. This reduces the twist and elasticity of the string while playing. XL is the Thickest among all Kitty String. XL gives more tighter bind and faster whip. This was designed for people who still feels that Fat type are bit thin for their play so we upgraded the thickness up to 13 Strands to make it more thicker and heavier for all types of division. Usually XL are used by Single A division (1A) .