Check the listing for details. 8 Octal Keyway Guide Pins - Repair Missing Guide Pins on Octal Vacuum Tubes. Condition: New. Listed at 33.95 USD. RCA Pin Straightener Roger Gould Microsoft Office User 2 36 2021-08-02T01:44:00Z 2021-08-02T01:44:00Z 1 70 402 3 1 471 16.00 Print 200 Clean Clean false false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 8 Octal Guide-Pin Keyway ReplacmentsRepair Broken or Missing Octal Guide Pins These octal repair guide-pin keyways are designed to replace broken or missing guide-pins on octal based vacuum tubes. The center guide pin keyway on octal-based tubes is often broken or entirely missing. Instead of throwing these tubes away, many can be restored using with these replacement guide-pins. Please note: that the bottom surface of the tube with a missing guide-pin must be flat – with no jagged edges sticking up. A flat surface allows the replacement guide-pin to seat flat against the base. The location of the guide orientation ridge (or keyway) can usually be seen on the base of the tube where the guide-pin has broken away. Carefully orient the replacement guide keyway. Refer to the photos for this procedure. With proper installation of the replacement guide pin, valuable tubes can be safely installed and used again instead of being discarded. Your purchase will be carefully packed and shipped FREE via USPS Ground Advantage.