Lyman Deluxe Neck Size DieIncludes Carbide Expander Button Features a precision machined and hardened die body along with a super hard and slick carbide expander button. The expander button also free floats on the rod to allow it to self center in the case neck and the slick button easily passes through the case neck. The result is a die that will reduce case stretching, increase case life and provide enhanced accuracy for the reloader.