The Tung-Sol 5AR4 is an ultra efficient indirectly heated dual diode, full-wave vacuum rectifier. Providing a mere 10V drop in B+ (plate voltage) at full current demand, this rectifier insures a strong, dynamic response to your sound. An excellent and reliable choice, the Tung-Sol 5AR4 comes with a classic brown base, tandem supported getter cup, dual mica spacers and full 30mm length internal plate structures. This tube is an excellent replacement of any GZ34 and 5AR4 rectifier tube.Tung-Sol It