What are the Yoga Foam Block Brick Stretching Aids? The two yoga foam block brick stretching aids help to improve stretching, posture & strengthens muscles. The yoga bricks each measure 7.5cm x 15cm x 22.5cm (3" x 6" x 9") When to use the Yoga Foam Block Brick Stretching Aids Use during yoga & Pilates to help extend your reach & develop core muscle strength How do the Yoga Bricks work? Each yoga brick is lightweight so you can lift it without straining. The yoga bricks are made from EVA foam & have a hardness of 26-30. Use the yoga bricks to develop your reach or place under your feet, hands or buttocks to provide support & aid posture during exercise.