The MDC Intelligent Stirrups are a revolutionary new stirrup design that positions your stirrups where YOU want them. Riders can now select any of three preset stirrup positions: traditional, 45 degrees or 90 degrees. You can customize your stirrups to the setting that best suits you, your horse and your riding application. This Feature is a First in Modern Stirrup Technology! The preset angle improves leg, calf and foot position, relieves pressure on hips, knees and ankles, as well as reducing leg burns. The MDC Intelligent Stirrups are easily retrievable, making your performance more precise and much safer. Additionally, the open stirrup angles greatly reduces the danger of being hung up and seriously injured. Each model comes with the patented, adjustable top. The MDC Ultimate Stirrup features a rubber protected hinged bottom.Please note that our hinged stirrups are true sized; a 5'' stirrup has an actual 5'' opening. Other hinged stirrups do not allow for the rubber. Their 5'' Stirrups meausre 4 3/4''.