On most of standard size binoculars models, there will be a thumb lever or wheel placed conveniently within reach so you can adjust the magnification without changing your grip or taking the eyepieces away from your eyes.
The perfect binocular for Birders and Hunters who require reliability, convenience, and precision. The Argos 8x42mm has an open-bridge design for a secure, ergonomic, and comfortable, one-handed ..