Pedal cleats are the metal or plastic item that attaches to the sole of your cycling shoe and clips into your pedals. Most shoes will accept most popular cleats (MTB shoes will take MTB cleats and Road shoes, Road cleats) but some may require adaptors. You need the exact cleat to match your pedals although some have either single release (twist outwards) or multi-release (twist in either direction) options. Cleats feature 'float', this is the amount of natural movement your joints require your ankle to move during the pedal stroke and is an important factor.