Are microwave's internal bulbs universal?

Are microwave's internal bulbs universal?

I need to replace the internal bulb of a Siemens microwave and I see internal bulbs for different brands look all alike, are they standard now? I mean I can just buy whatever I find on amazon even if it says is for another brand?

ANSWERS:

@veetee they are not standardized but yes, you can use whatever brand you like for as long as it a. fits the connection and mounting bracket, and b. has the same wattage.