This instrument and technique minimize blood loss and risk of hemorrhage through the severed cord. Utilizes twisting action which effectively closes the severed cord. Used with a standard, variable-speed drill (not included). May be used on any age bull, (500 to 900 lbs. work best) Easy to use and faster than many other forms of castration. Used with a standard, variable-speed drill (not included) - a cordless unit is best for convenience and safety. Should only be used with a variable-speed drill with a 3/8" chuck. May be used on any age bull but is an especially effective method to use on older, heavier bulls (500 to 900 lbs.) where it is important to minimize the risk of blood loss, swelling, and infection. Easy to use and faster than many other forms of castration. Field tested by veterinarians and cattle producers. Patented. Equine Model also available which works well on larger cattle