The Black Lines magnetic bracelet has 4mm diameter 5000 gauss magnets in each link. This bracelet has a 9/16" wide x 15/16" long link with 17 rare earth magnets in 8 9/16" length. It has a magnetic therapy pull strength of 300 grams. Magnetic bracelets are the strongest magnetic therapy for hand (arthritis tendinitis), wrist (arthritis, tendinitis, carpal tunnel), elbow (arthritis, tendinitis) and shoulder (bursitis, tendonitus, frozen shoulder) on the arm they are worn. However magnetic bracelets will often help neck, back and knees. Determine magnetic bracelet size by measuring the circumference of the wrist and adding 3/4 inches.