Switchcraft number is MDSL2A
Size is 2.5 mm. This jack will accept 2.5 mm or 3/32 inch mono audio plugs.

My Spider-Sixty

My XR Combat Wing

Charging Plugs and Safety Test LED
When the plug is inserted into a newly wired plane, the LED should light. If it doesn't, something is wrong even if the plane correctly switches off and on when the plug is inserted and removed. The problem is that you have the two positive connections reversed on the switchjack, and if so, this must be corrected before charging is attempted, else the charger's voltage will be connected to the receiver, possibly causing damage to the receiver and servos. If you plan to wire several planes with switchjacks, I recommend making a safety test plug.