The base looks like a Type S, as far as replacing it with an LED in a DIY fashion the leads are plain old 110v AC. You don't want to put much more than 5w of LED in there, so you can probably get away with a basic capacitive dropper circuit that matches the LED you choose. Someone mentioned a starter, that is in the bulb base, not the socket on the microscope on these.
The base looks like a Type S, as far as replacing it with an LED in a DIY fashion the leads are plain old 110v AC. You don't want to put much more than 5w of LED in there, so you can probably get away with a basic capacitive dropper circuit that matches the LED you choose. Someone mentioned a starter, that is in the bulb base, not the socket on the microscope on these.