The cleats sit recessed in the sole of the shoe allowing the rider to walk around which when off road can be important for negotiating obstacles and difficult terrain. They still give a solid fixing to the pedal allowing the rider to pull and push and so getting more power and more control through the pedal stroke. They designed to be very easy to clip in and out of to and can be released by sideways movement and hard upwards movement. They are ideal for those who do not ride very much and so dont want to be securely fastened in the pedal. We do recomend for those who want to ride off road on more demanding trails that you use the single release cleats.
The Shimano SPD pedal systems have become so popular that the term SPD is now widely used to describe an MTB pedal system, even if Shimano are not the manufacturers.
SPD multi-release cleats
Allows your shoe to be disengaged by rolling or twisting the foot in any direction
The cleat will even release with sufficiently hard (and considerable) upward force, minimising the risk of toppling over with both feet still clipped in
Designed to work with all open design pedals