The A70Lf is an Achromatic Refractor with 70mm (2.8”) of aperture. Its focal length is 900mm (3 ft.) with an f ratio of 12.9. Its light gathering is 100 times better than the human eye and has a maximum (realistic) power of 143X. It weighs about 4 lbs.This package combines sharp optics and a rock solid, light weight mount. It takes just seconds to place the telescope on the mount and you are ready for an evening of observing.The Vixen PORTA comes equipped with two fine adjustment handles for whole circle slow motion in both directions, very useful in searching and tracking celestial objects. In addition, these are great mounts for terrestrial viewing. Our gear drives make it a simple matter to precisely track a planet or a ship on the horizon by simply turning the elevation and or azimuth control handles. The “World-Standard” dovetail attachment system on PORTA was developed by Vixen. This allows the PORTA to accept various dovetail mounted optical tubes and binoculars.