vacuum tube==========Hign-concerned Chemical : NoneChannels : 2 (2.0)Model Number : 5881Maximum Power Per Channel : NO POWEROrigin : Mainland China vacuum tube The has good linearity low noise and good reliability The tube is designed for service as power rectifiers in AC operated receivers which require high currents. The service life longer and the failure rate greatly reduced. The special with signal and has low noises output. Durable and with a long life. Item Weight 12.3 ounces Manufacturer YQIRONRI Item model number YQIRONRI Batteries required No Package Dimensions 0.39 x 0.39 x 0.39 inches