These are new shin guards not sold in Japan. The included manual says they are for soccer, but ennui is a brand of aggressive inline skate protectors from the inline skate manufacturer POWERSLIDE. I think ST stands for street, and they can be used for street sports such as skateboarding and BMX, as well as inline skating. - Brand: ennui - Size: L/XL - Color: Black They are made of thin, breathable fabric. There is non-slip material on the inside of the upper part, and the outside is wrapped in rubber and secured with Velcro. The front pad has a pocket-like structure on the inside with a black rubber pad inserted. I think it can be removed, but since it's new, I only peeked inside. They are thin, so I don't think they will be noticeable under your pants. Includes the instruction manual. Thank you. #ennui #shinguard #shinguards #POWERSLIDE #shinguard #protector #soccer #skateboard #aggressiveinlineskate #aggressiveinlineskate #BMX