No, I have both dremel and wen tools. The keyless chucks will not interchange.
I have an old working Dremel and the chuck didn't fit the Wen rotary tool.
I'm not positive, but I think the size for the rotary tool accessories are pretty much universal. Seems as though they all are compatible.
There is no universal size. I have three different makes and models that this will not fit. Good thing is the return policy.
Not positive, but pretty sure all rotary tool accessories are compatible across different brands. It would make sense to keep it that way as many people own different brands and companies would want their product to work with other company's accessories also.