What do XT and XXT mean?

Almost all of our  chew tools come in 3 color-coded toughness levels - standard, XT, and XXT.  XT stands for "Xtra Tough" and XXT stands for "Xtra Xtra Tough" 

• Soft / Standard = always the softest level in any shape.  This level is best for mild chewing (for those who need to chew, but don't usually chew through anything they chew on.)  
• XT / Medium Firm = firmer, but still fairly chewy in most shapes, especially the long slender back-molar ones.  It's closest to the firmness of pink pearl erasers.  This level is best for moderate chewers (for those who have chewed through the softest level or who have chewed through other items)
• XXT / Super Firm = this is the most rigid level.  Nothing chewable is indestructible, but this is usually the longest lasting level in any given shape for very avid / aggressive chewing.