The MDF® Trömner Hammer > Light > HDP Handle (aka Tromner or Troemner) is a versatile 4-in-1 dual mallet-type reflex hammer designed for eliciting myotatic and cutaneous responses in adult and pediatric patients. The ergonomic HDP handle lends the hammer a lighter weight while providing the user with greater control during percussion. This updated design is based on the classic reflex hammer invented by Ernst L.O. Trömner, MD, a director of the Neurological Hospital at St. Georg and professor at the University of Hamburg.