Orion 08453 10x40 E-Series Monocular (Black) Economical and portable, this 40mm aperture monocular provides bright magnified views on the go 10-power magnification allows you to obtain close-up views of distant targets Big, 40mm objective lens gathers lots of light for good views in low-light conditions such as dusk, dawn, and in overcast weather conditions Close focus of 22 feet lets you study nearby targets with 10x magnification 3.1 degree field-of-view