The Oxygen AR 1.1 Aggressive Inline Skates in black, size 31.0, are a rare find from the 1990s. With a US men's shoe size of 12.5, these skates are designed for aggressive skaters looking for high performance footwear. The wheels are kryptonics wheels, and are very smooth, ready to skate. The brand, Oxygen, is known for producing quality inline skates, making these a valuable option for those seeking top-notch gear for their skating adventures.