Is the DC Agetec stick region locked?

I found a agetec stick for sale and the seller stated its for Japanese dreamcast only, i thought the DC controllers were never region locked to specific country, first time i even heard of this, is it true?

No controller for any system has ever been region locked.

thanks for the quick reply, i bought the stick now, gonna dust off my good ol DC, now hopefully i can find a USB converter for it to work on pc.