811A Penta Labs High Mu Power Triode Single (1) Tested Tube CB Ham Radio | eBay
File:Vintage Grebe MU-1 Synchrophase With Gold-Plated Escutcheons, Battery Operation, Circa 1925 (9120006960).jpg - Wikimedia Commons
Michelin 16" Standard Inner Tube w/PV/PRV-78 Center Metal 90 Bend Tall Valve Stem (MT/MU/120-140/90, 150-160/80) - 55944 Harley Motorcycle - Dennis Kirk
5751 Tube - Audio, High Mu Twin Triode, 5751/12AX7/ECC83, special purpose, MFR: JAN / GE