Don’t be easily deceived by the Viper’s rugged exterior. The roller is made from high-grade German foam, and it houses a precise vibrator that you can set to 3 different frequencies. The roller can be then used during your exercise routine to work on your muscles, posture, and flexibility. The Viper is touted by some eminent athletes as the possibly the most effective fitness roller out there. Expect to give your pet cat a run for its money when it comes to being lean and flexible!