Come and see our amazing products.These spiked balls are made of durable solid rubber to withstand any body weight. These spikes will not bend and are safe for skin. Odorless and will not cause skin allergies. Just lean on the massage ball, then use your own body weight and gravity to massage your neck, shoulders, back, feet, muscle joint to relieve muscle pain. Or you can sit on a chair, lay on the bed or a yoga mat to massage your whole body, relax tight and tense muscles. Pls confirm further with us if any query about packing info, inventory status and time schedule.