Sylvania 1L4 Tube - NOS in the box. Tested good on Hickock 539B | eBay
Amazon.com: 1/4" Side Male Thread Quick Connection 1/4" Tube Hose Equal Type T Water Fitting with Sealing Ring Reverse Osmosis Aquarium Tee-Y-1l4 : Industrial & Scientific
1L4 (DF92) Pentode. A vacuum radio tube by GE General Electric, U.S.A. #20654 | M-Ware
1L4 | CIFTE | PENTODE TUBE At 3 € HT on Electols
1L4 | Tullielettronica.net
OLGYN Black Air Hose Fittings 1/8 1/4 3/8 1/2 4mm/6mm/8mm/10mm PC PCF PL Tube Connector Pneumatic Quick Coupling Pipe Hose Fitting (Size : 10-02 (10mm-1l4), Color : SL) : Amazon.it: Commercio, Industria e Scienza