I would not go with an offbrand. I have learned that when purchasing any kind of mod, from $5 to $500.. when you try to save a few bucks by purchasing the non mainstream item, you're asking for trouble. Especially something like the smart top for the 170. You do not want the nightmare or hassle. Have you seen the configuration? Do yourself a favor and just get one from the slkstore. I hope you signed up for the group smartop buy.