Will it fit fairywell 508? Thank you

The description lists FW 508 as a compatible toothbrush, so Yes.

Are these compatible for aquasonic black series?

The fitting this toothbrush goes into is 1.75 inches long and 3/8 inch wide. I have a picture in my review, but can't post pictures here. If your toothbrush has that kind of fitting it may work. There is no standard, and I believe the manufacturer's website has a list of devices this will fit.

Is it compatible with the colgate 360 electric toothbrush?

I've tried to upload a picture of the fairywill toothbrush head so you can check compatibility, but evidently that's not allowed. I'll post it in a review if I'm able. It may fit your colgate toothbrush but you really should check with the seller. Sometimes that's not possible so I measured it all. The brush part fits on a round mount on the top of the toothbrush. It is 1 and 3/4 inches long and about 3/8th inch at the bottom and a little over 1/4 inch at the top. There is also a small "T" at the bottom of this where the toothbrush locks in. So, if you can measure the mounting section of your toothbrush base then you can perhaps tell if it's compatible.

Hello! i have an oral b electric toothbrush. will this possibly fit?

Seriously doubt it but don’t know for sure. Also, I seem to recall oral b uses a circular head with a different vibration pattern. These are more the Phillips style brush but doubt they would even fit them. I use them with a Fairywill toothbrush.

Units	6 count
Brand	Mullburry
Format	ELLIPTICAL
Age Range Description	Adult

Mullburry Replacement Toothbrush Heads Compatible with Fairywill Electric Toothbrush, Model FW-507/FW-508/2011/959/917/551, D1/D3/D7/D8, W Shape Design Planted with Nylon Bristle (6 Pack - Black)

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