REEHUT Foam Roller - Firm High Density Muscle Rollers with Free User E-Book (12 Inches 18 Inches 24 Inches & 36 Inches) 4 Sizes Available - Measured 12", 18", 24'' and 36". 36" is large enough for working the entire body. 12" 18'' & 24" are easy to store and transport High-density And Extra Firm - Firm enough to support all body types without losing shape Made from EPP, which is lightweight, nontoxic, Eco-friendly, recyclable Release Myofascial trigger points and loosen knots in muscles, especially for back, calves, shins, quadriceps, IT band, hamstrings, Adductor, Piriformis, lats, and glutes FREE 18 PAGE E-BOOK to show you how to foam roll correctly + safely.