Strayfield 1.21.103S Triode Valve is a vacuum-tube component identified by model numbers 1.21.103S, 121103S, and 1.21.136. This Strayfield triode serves as the amplifying element in electronic circuits that require a vacuum tube. With its specific identification codes, it offers a precise replacement option for equipment that uses the 1.21.103S/121103S designation.
