Nurfl is a set of simple drop in objects you can use to access your TeraWurfl device database. You obviously must have TeraWurfl installed and the webservice endpoint available.
You can find a full listing of capabilities provided by the Tera Wurfl api here.
To retrieve a device you'll need to work with the NurflRequest Object.
//instantiate with current request object
var nurfl = new NurflRequest(Request);
//instantiate with user agent from request
var nurfl = new NurflRequest(Request.UserAgent);
//or from string
var nurfl = new NurflRequest("Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A293 Safari/6531.22.7");
//retrieve the device
var device = nurfl.Get(webserviceurl);
//retrieve specific capabilities
var device = nurfl.Get(webserviceurl, "is_wireless_device", "brand_name", "model_name", "is_tablet");
//do fun stuff
device.IsMobileDevice();
device.IsTablet();
string brand = device.GetCapability("brand_name");
string model = device.GetCapability("model_name");