Hello,put on the CPL filter or mist filter then screw on the Variable ND on top.Stacking filters in general can create different effects and bring out your creativity. The only caution is that as you put more filters on the lens you can create vignetting or the cutting off of the corners of your picture. This can happen more with wide angle lenses. You’ll also get vignetting by stacking neutral density filters, depending upon which ones you stack and the order you stack them you’ll get varied effects. We don’t recommend stacking a VND filter but if you do, make it the last one because of the threads. 

You can determine distances anywhere with the device. 

The battery has a capacity of 750 mAh and can be used 3,000 to 5,000 times after fully charged. Under normal use, a single battery can be charged 10,000 times. 

That is the case, and there are also yards and meters. 

yes it is compatible