Monocular HookUpz 7x18 mono with iPhone 5 Smartphone Adapter

Describes the internal structure of a pair of binoculars, thereby further subdividing the different types.

A very compact long-range scope through which you observe with just one eye.

The second specification in the binoculars’ model number is the front lens diameter. The larger it is, the more light the binoculars collect.

These eyepieces have a relatively large eye relief. It is possible to wear spectacles while observing and still benefit from a comfortable viewing position.

Watertight optics are equipped with special seals and are gas-purged. This is usually with nitrogen or argon gas. Since these gases are heavier than air, they cannot escape.