Fat Grip Silicone Barbell Grip, The Ultimate Arm Builder INCREASE ARM SIZE AND STRENGTH - These barbell grips will take you goals to a new dimension with noticeable results! SCIENTIFICALLY PROVEN - Science has shown that using a thicker diameter bar causes much greater muscle activation in the arms which leads to incredible muscle size and strength gains. WORKS INSTANTLY - Fat Gripz work by instantly converting barbells, dumbbells, pull-up bars and cable attachments into thick bars (also known as axel bars, fat bars or super bars). BEST VALUE - The same muscle building effects as the name brand grips for 1/3 OF THE PRICE!!!