Good value - OpticsPlanet Exclusive Firefield Nightfall 4x50 Night Vision Monocular

This is a lot of NV for the money. I saw many reviews with focusing issues, but many more that said to just follow the focusing instructions. I can adjust mine to be crystal clear. My only issue is that the eyepiece/ diopter has so little resistance to turning that it will move as you look through it or store the unit. You must tweek the eyepiece focus regularly and then adjust the main objective focus for distance variation. The main thing is that the diopter isn't an adjust once and forget it like a rifle scope.
All things considered, this is a very functional NV unit. It's has good hang time on its common AA batteries. It seems to be well made and ranges out to around 150 yards max with the IR. They should address the lens cap issue with some sort of retainer. I leave mine in the case when hunting at night. It would be easy to lose in the dark and daylight will damage this unit without the lens cap on.