TSN-774 straight spotting scope body onlyPlease note: additional eyepiece is required in order to operate. Kowa 77mm XD lens model - superior performance in a compact body. The performance and compactness of these spotting scopes are second to no other scopes in this class. The housing is waterproof to JIS protection class 7 and filled with dry nitrogen gas to prevent the lens from foggingThe PROMINAR models TSN-773/774 using an XD objective lens with low dispersion properties to diminish chromatic aberration. The well established Kowa focus system has progressed to a new dual focus system. The quick focus, with a large and easy to turn knob, will focus from infinity to five meters in two revolutions. The fine focus, with smooth movements and pinpoint accuracy, is extremely useful at high magnifications and for digiscoping systems. When an XD lens (eXtra-low-Dispersion-lens) is paired with a concave lens with special dispersion properties, chromatic aberration is almost eliminated. The performance of spotting scopes with XD lenses is very close to that of our flagship models with fluorite crystal. Kowa TSN-774 77mm Straight Spotting Scope Body