Dioni
Flashlight Enthusiast
Yes, that is exactly the same bulb. My WF-500 is completely stock with no modifications and will only work with button top 18650's. There must be different WF-500's where the bulb spring makes contact with the battery itself. See the end of the battery tube in the picture? This is what mine looks like.
Actually it has some differences
Based on the bulb that appears in the pic, it is a philips and maybe your model could be the wf600, but you deleted the logo.
You can even have problems in the same way other lights that have flat contact.