The Big One by Tiger Tail is the new king of foam rollers and is sleek and powerful. Easily break up muscle knots and release tightness. Rigid hollow core, hefty foam construction. Super sturdy design. Thick, heavy-duty foam. Built to last with Tiger Tail’s stamp of quality. Won’t break down. Check out our book “Happy Muscles” to help identify muscle knots/trigger points our tools can help with.