Check the listing for details. Microscope Objective, Ultra Compact 50X x 0.90 NA, Achromat, New. Condition: New. Listed at 450.00 USD. Ultra compact and lightweight microscope objective Power: 50X x 0.90 NAWeight: 3.0 gSize: 12.7mm dia x 13.5 mm longResolving power: Less than 1.0 μm on-axis for 550 nm Chromatic aberration corrected over 400-750 nm rangeWorking distance for 550 nm: WD = 0.62 mm The ultra small size, lightweight and high numerical aperture makes this objective especially useful for scanning images and focusing or condensing applications in biotech, fluorescence spectroscopy and laser fiber delivery systems. Optical system is a multiple lens infinity-corrected achromatic lens. The front focal position is 0.62 mm outside the front edge of the housing.All lenses are AR coated with BBAR 400-750 nm, R < 0.7% per surface.The back focal plane position is 9.63 mm back from the front edge.