The TruForm equine armature is made of the same durable materials as the Truform figure armatures. The rigid ribcage is made of rigid foam that will not flex side to side and is best if your horse is moving in a straight line. You can cut the foam rib cage to modify it for a rearing horse. The pelvis and extremities are made of urethane plastic and the head of urethane foam. The skeleton can be raised at the center pipe by a t-screw adjustment. The TruForm Equine Pro is 1/4 scale (15" at the withers) and 1/6 scale (10" at the withers) to a 15-15.2 hands high quarter horse. This scale compliments our 18" and 12" figure armatures. The bones can be lengthened at the femur, pelvis and cannon bones. The armature can be used with any type of oil-based modeling clay.