25x100 FB is for the amateur astronomers who are experienced in using binoculars.  The major difference between 25x100 FB and the 70, 80 and 90mm binoculars is the prism housing.  The 25x100 FB's has better prism mount so that the front prism and rear prism are in much

better alignment.  Also, with the 25x100 FB prism housing, the objective tubes are in perfect parallel positioning with eyepieces.  The point is that the better collimation, the minimum prism light cutoff and more even focus are achieved.  

Another major improvement is the blackened inside of the objective tubes.  It doesn't use the common anti-dust paper with sticky oil to trap the dust and dirt - this makes the inside surfaces reflective and shiny. 

Instead, all internal surfaces of 25x100 FB are sprayed with a non-reflective black paint before assembly to decrease the reflection and increaser the contrast. 

This feature is only see in a few very high-end German and Japanese models.

25x100 FB has a rubberized all-metal body with hinged central bar as the mount.  The design itself is more waterproof and shock-resistant than most of the giant binoculars.  It's individual focus, 4.6 kgs in weight and 44.6 cm long.  It's fully multi-coated and has accessible collimation screws.

Classic Binocular

The new Classic Binocular 20x80mm offers one of the highest performance/price ratios of any binocular on the market. Not only does it feature huge 4-inch objectives, it has broadband multi-coating on all air-to-glass surfaces, all-metal construction, and a built-in aluminum mount- all at a shockingly-low price. An easy-to-operate center-focuser is used (rarely found on 100mm binoculars) which makes this model a great choice for terrestrial viewing, which typically involves frequent and wide focus adjustments. The large wide-angle (2.8° FOV) eyepieces have winged eyecups that very effectively block stray light. It has relatively long 18mm eye relief, so it can be used by those that wear glasses*. The weight is a very low 8.8 lbs., so many reasonably-priced mounting options are available, from a standard tripod/head, to the Unimount parallelogram mount. Includes ocular and objective covers, as well as an aluminum-framed case.

Zoom Binoculars

Zoom model can capture a panorama at low power and then zoom in to pick up the details at higher powers. Zoom binoculars are excellent for sporting events, birding, nautical applications, and surveillance. Zoom binoculars, however, offer narrower view than the fixed-focus binoculars. 

We carry the best selling zoom binoculars from full size to giant size.  All zoom binoculars come with Bak-4 prism, broadband multi-coating on the objectives, rugged rubberized metal bodies, all-glass lenses, right ocular diopter adjustment, brass 1/4-20 tripod adapter threading, case, caps, and strap.