This is product focuses on long-range photography and surveillance.
This telephoto zoom lens can be clipped onto a conventional smartphone in order to convert it into a surveillance and observation tool.
Whether you're doing covert field work, helping a buddy spot where their rounds are impacting on a distant shooting target, or you're simply taking wildlife photos on a hike... this lens offers a decent balance of quality, functionality, and price.
You can adjust the focal length to dial in clear photos at a wide range of distances.
The best camera to use for field work is the one you've got on you, not an expense one that you left at home.
And this lens allows the phone in your pocket to be pressed into service without great added bulk in your field bag.
In addition to the included smartphone mounting clip
(which can slide to a wide range of positions and opening sizes in order to work with essentially every smartphone currently on the market, regardless of where the built in lenses are)
this product also has an included eye cup.
Swap the mounting clip for the eye cup to use this telephoto lens as a hand-held monocular.