These are I presume Chinese heads and might possibly be the same as Benro. If so, then take care. I read an online review of a Benro head, and the internal construction is shocking. Really shocking. For example, the locking knob works by pushing a screw into an aluminium surface. With time a groove is worn into the aluminium. I'm sorry I cannot find the review, but a Google might throw it up. As I say, they might not be the same as Benro, but then again ...