The material used is First Quality Vegetable Tanned leather . ✓ Thickness approximately 3.5 to 4 mm ** The "snake tongue" is a strip of leather that is subdivided into two strips in bifid form (like the snake tongue) to be able to knot to any surface. It has the advantage that it does not depend on a buckle anchored to a fixed area and also gives you all the mobility of the arm. "chest contour" from 80cm to 115cm ✓ "biceps contour" from 25cm to 45cm ** In case you have a doubt or believe that your measure is not worth or is special, send us a message, we will be happy to help you. heavy quality good finishing  THANKS FOR SHOPPING!  (GLOBE ENTERPRISES) KEEP SHOPPING  AND HAVE GREAT DEAL WITH US.