ALPHA AS FUCK (Neon Pink)
In the videos I actually wear X-Large. I can also wear Large or a snug Medium. I am a little over 5`9 and a little over 180 lbs. The photos you see, everyone is wearing Large/X-Large.
Keep in mind the MAJOR difference in sizing is just the length (most tank sizes in the chest area fit pretty similar).
I would say the following sizes would work as a rule.
If you are below 5'4 (or female) get Small
If you are between 5'5'-5'10 (and/or a small or medium build) get Medium
If you are between 5'7-5'11 (and/or a medium+ build) get Large
If you are between 5'9-6'1 (and/or have quite a lot of muscle) get X-Large
If you are 6'0+ (until maximum height 6'5) get XXL
Women should wear the S or M. Most guys are either M or L (or if you are jacked/are taller, XL). Personally I like to wear the L or XL (whereas for t-shirts I usually wear a M or for leg day a L).
Made of 88% Polyester, 8% Raylon, 4% Spandex. Machine wash on cold.