Extremely cheaply made weirdly shaped buttons x y z buttons in particular compared to the actual thing just broke after 5 or so years of use but to be honest had been pretty much limping along for the past 3 with the cover on the end of the cable having split off randomly and left me with bare wires dangling out of the genesis only about a year after i got the controller

If you want a cheap substitute i highly recommend hyperkins sixbutton genesis controller which is made much closer to the quality and specs of the 6button sega controller

Compare to the genuine article which while considerably more expensive ive still seen them in excellent condition now nearly 30 years after the release of the original model 1 genesis