Don't buy this stem
Won't hurt your knees lightweight cheap
Never stays put cracked on its second season of light riding
I would never recommend this stem to anyone. I am a very casual rider mostly park with a little low risk street occasionally. Nothing about the way I ride my bike should ever break crack or bend anything and yet this stem managed to crack on the lower steerer tube ring a month into my second summer with it. Before it cracked it was notorious foe moving around on the steerer tube. It held the bars great front to back but moved around the steerer tube quite often.