Yoga Studio Recycled Chip Foam Full Yoga Blocks (10 Pack)Pack of 10 The 5. 5kg (12lb) density of these recycled chip foam yoga blocks makes them the firmest chip foam block available. (cheaper foam blocks lack the density and durability of these). Blocks enhance your practice by supporting, stabilising and aligning the body. Sit on one to raise your hips for a straighter spine, or put four together for a classic shoulder stand support. These chipped foam blocks are almost the same as our regular blocks but