BlackSunnyDay Size Chart: 
Small:
Height(cm): 145-160; Chest(cm): 75; Waist(cm): 60; Hip(cm): 75. 
Height(in): 57-63; Chest(in): 30; Waist(in): 23; Hip(in): 29. 
Medium:
Height(cm): 150-165; Chest(cm): 80; Waist(cm): 69; Hip(cm): 80. 
Height(in): 59-65; Chest(in): 32; Waist(in): 27; Hip(in): 31. 
Large:
Height(cm): 170-180; Chest(cm): 90; Waist(cm): 78; Hip(cm): 90. 
Height(in): 67-71; Chest(in): 35; Waist(in): 30; Hip(in): 35. 
X-Large:
Height(cm): 175-185; Chest(cm): 100; Waist(cm): 90; Hip(cm): 100. 
Height(in): 69-73; Chest(in): 39; Waist(in): 35; Hip(in): 39. 
XX-Large:
Height(cm): 185-195; Chest(cm): 110; Waist(cm): 95; Hip(cm): 110. 
Height(in): 73-77; Chest(in): 43; Waist(in): 37; Hip(in): 43. 
When ordering, we recommend you choose your size based on your height. If you feel you exceed the weight range then you may want to go up in size. 

Zentai is a tight-fitting catsuit made of stretchy lycra spandex fabric that covers the entire body, also the face. Zentai comes most likely from japanese word Zenshin Taitsu, that means "full-body tights". 
How to breath? Since Zentai is made of fabric and not for example latex, you can breathe trough the mask quite easily. The basic shiny zentai suit is often made of nylon/lycra blend, a similiar fabric to what is used for swimming suits and bike shorts. 
How to see? You can see while wearing a zentai, enough to do simple tasks. The quality of vision is relative to the thickness and colour of the fabric. Generally speaking dark colours gives you better vision. 
How to get into? The basic zentai has a zipper in the back. So you can easily get into your zentai suit. And you can select "crotch zipper" option.

ASIN: B00HG9EU04