Not sure if it has a model # as I got it as a real work in the lard kind of watch but It had a screw down back. When I went to order a new one, I just went cheapo and for $35 got one that looked the same but the back had 4 little screws. Just thought i would ask. Screw down back means more quality usually and my old one last 10 years, lost all it's rubber cushioning(actually lookled neat in brushed stainless)and then it just froze and I fiddled with it, replaced battery but no go. So all I want to know is the screw down back no longer what they use? Just info for me.