There are a few members using that device, but it’s an old generation of zwave and has a number of limitations that mean it’s not that popular. It can only be used with other Z wave devices, it can’t be used for any other Smartthings functions like changing the mode or running a routine, and it can only be used with Z wave devices which are within one hop, which means about 40 feet. It’s also sort of tricky to get set up.
Since you already have one, if you do have other Z wave devices nearby that you want to use with it, you can. Just search the forum for that model number and you should find the discussions of it.
If you want to add additional Devices in the future that would work better with SmartThings, be easier to set up, and wouldn’t have the device/distance limitation, take a look at the buttons FAQ. There are quite a few choices.
But there are certainly some people who have that one, usually because they previously used it with a different system, and you should be able to find some people to help you with it in the existing topics.