This is a set block measuring 20mm x 30mm. Both widths are commonly used in overseas competitions. The 20mm is the same as a parallel set (MMS), and the 30mm is used outside of competitions, such as for Gods Of Grip (UK) certifications. I always use these to close a set, ensuring I close at least a 20mm (parallel) gap. The material is aluminum. The length is 100mm. There are some scratches. Please judge the condition from the photos. The first photo shows how to use it, but this product is only the set block (the gripper is not included). Disinfected. Thank you. #gripper #ghp #coc #setblock #handgrip #gripper #gripstrength #forearm