Seetronic SJP3C TRS 1/4" Locking Panel Mount Jack D Series Designed to panel mount into a standard D-series punch-out. The standard knockout for a D-series product is approximately 0.840" or 21.3mm. 27/32" will also work.   Would you like connectors...

Seetronic ST229L 1/4" Panel Mounted Jack - Mono

Seetronic ST230 1/4" Panel Mounted Jack - Stereo

Elite Core CSO-50 Pack of 50 screws for attaching D-Series connectors to threaded panels. M2.5-0.45 x 8mm phillips machine screws.

Elite Core CSP-50 Pack of 50 Screws and Nuts for attaching D-Series Connectors to Wall Plates & Panels. M2.5-0.45 x 8mm phillips machine screws with nuts.