The Shimano SM-SH51 are the cleats that come with your Shimano SPD Pedals. The SH51 cleats are black and have four degrees of float for your feet. Compared to the SH-56 multi-release Cleats, these are much more secure and are generally preferred for the experienced rider. To get out of your pedal, you’ll have to swing your heel out a bit more than the SH-56 Cleats.
Features - Four degrees of float - Slightly greater release angle than Multi-Release Cleats