Who makes the Khypermedia 8x+/- DVD-RW drive

Who makes the Khypermedia 8x+/- DVD-RW drive.

If there’s more than one OEM, how can I tell which is which by the serial number or by the country of manufacture?

If there’s more than one OEM, which is better?

Thanks

I think the +Rs are BenQ and the +/-Rs are LiteOns