OMAX 6X-200X Binocular Zoom Stereo Microscope Body+2X Barlow Lens Total magnification: 6X-200X; Zoom ratio: 33.4:1; Head: 45 degrees inclined 360 degrees rotatable binocular head; Diopter: adjustable on both eyepieces +/-5dp Eyepieces: 30mm widefield WF10X/23 and WF20X/12; Objective: zoom 0.6X-5X; Barlow lens: 2X; Interpupillary distance: adjustment 2inch - 3inch (50mm - 75mm) Working distance and field of view: see the table of working distance and field of view of add-on barlow lenses; Mounting size of barlow lens: 54mm female thread Body mounting ring size: 76mm; Focusing mechanism (not included): refer to the description of boom stand or other stand (sold separately) 5-year warranty against manufacturing defects