Lorina Flexi Stirrup Irons – Safety Stirrups with flexible joints.With flexible sides to absorb more impact and therefore lessen the impact on the riders joints. Available in 4 1/2″, 4 3/4″ & 5″Stirrups should be the correct size for the riders feet. Too small and there is a chance of the foot getting stuck in the stirrup in the event of a fall, too big, the foot can slip through. The way to tell the correct stirrup iron size is that there should be a clearance of 12mm on each side of the foot.