Bioflow Sport is designed to complement an active lifestyle,with a winning combination of patented magnet technology teamed with a durable,non-tearable silicone sports wristband. The Bioflow Sports wristband is water resistant. Please measure your wrist carefully and order a size that fits comfortably and is not restrictive. Bioflow Sport does not need to be tight to the wrist. Please note: Bioflow products should not be worn by anyone fitted with a heart pacemaker or other implant that could be affected by a strong magnetic field.