These stirrups are made from aircraft-quality aluminum and cast in a metal mold. They are then hand sanded for a slick finish and then hand buffed to a high luster. A traditional stirrup places your foot at about a 30 degree angle to the horse misaligning the bones in your knee and ankle. The outside of the slanted stirrup is longer than the inside so that when you turn the fender the stirrup is parallel to the ground. This relieves the pressure from your knees and ankles. These are great! For women with a small size or youth.