4fit Heavy Duty Arm Blaster Body Building Bomber Bicep Curl Triceps New The contoured design allows arms and shoulders to be isolated while keeping the back and elbows locked in curling position. Used to enhance bicep curls, allows user to build lean and big muscle Top Quality Biceps Isolator, Arm Blaster . Heavy Metal Buckle for Clip keeps Belt Secure. Used to enhance bicep curls, allows user to build lean and big muscle.