Helikon Blood Patch Set of 2 Black B- Set of two 3D hook-and-loop patches with blood type information. Very legible, progressive, and modern appearance Durable, flexible and easily washable. Professional look with raised 3D layered effect One piece construction with hook side hook-and-loop backing. Rounded edges. Matt finish Great for medics, first responders, rescue, airsoft, travellers or general safety Material: 100% PVC. Dimensions (each): 1.5"x1" (3.8x2.5cm). Weight (pair): 4g