Simply Smooth xtend Between Dry Shampoo 7ozxtend Between Dry Shampoo is botanically blended and keratin infused. This sodium chloride-free shampoo is for all hair types, whether or not a Simply Smooth Keratin Treatment has been applied. xtend Between Dry Shampoo refreshes and revitalizes hair between regular shampooing, and rids hair of environmental impurities while deodorizing and cleansing oil from hair.