bar grips are 2 thick and made from a durable non-slip rubber. The inner diameter of the grips is the perfect size to fit any type of weight barbell, dumbbell, pull-up bar, or kettlebell. The thick grip adaptors are made with a durable non-slip rubber with a cross hatching design for added grip. Barbell grips are great for rapid increase in forearm and biceps strength and size. Fat grips help to reduce calluses, hand pain, and stress on your joints compared to the use of standard metal bars.