Show Me How To Measure

1. Hold your arm out straight (without "making a muscle"), palm up, with your arm relaxed. 

2. Measure (or have someone else measure for you) the circumference of your arm at the middle of the biceps muscle.

3. Pick the corresponding size of arm band from the sizing chart below.

4. If your arm measurement is right on the borderline of two sizes, choose the larger size to get the best fit and the most grip.