Smyths sell 100's of these excellent  BARSKA Binoculars ,ZOOM 10-30 X 50  GLADIATOR AB10168 every year !  Being rugged and lightweight is one thing but the bright, crystal clear image is really first class. These BINOS are top, top quality  Reverse Porro  Prism with handy strap & carrying case. Lightweight and really high powered ideal for birdwatching and hiking, fishing. Precision Binoculars with a strap and case 

The 10-30x50mm Gladiator Zoom Binocular from Barska is designed for long-distance terrestrial and astronomical viewing. The variable magnification range of the binocular allows the viewer to scan a large field of view and then zoom in on the selected object for a closer and greater detailed look. A zoom thumb-lever for making quick and smooth magnification changes is featured. Fold-down eyecups are incorporated into the eyepieces for comfort viewing with or without eyeglasses.

magnification... 10 times

objective lens 50 mm

Field of view 195 feet @ 1,000yards

Close Focus  26 feet

Prism Glass  BK-7

Exit Pupil..5 mm