A cheaper and smaller, lightweight option to the Seago Binocular is the Monocular.
The Seago MON842 is a light weight heavy duty monocular incorporating a hand bearing compass and range finder.
The monocular is splash proof and nitrogen filled to avoid misting and water ingress. They come in a durable protective carry case.
Objective lens dia: 42mm
Field angle: 7°
Exit pupil: 5.3mm
Eye relief: 19mm
Prism type: Porro BAK-4
Field of view: 122m at 1000m
Lens coating: Multi coating
** COMPASS ZONE B: Areas between 40° North latitude and 60° North latitude