Please contact us if you have any question. We will work with you to solve any problems. Thank you! This microscope can not be connected with any auxiliary barlow lens directly because the thread of the objective lens cover is special. However, we found out from the reviews and Buyer Questions& Answers that some buyers can add auxiliary objectives to extend the working distance. The screenshot is attached. Interested guests can try to contact these buyers for a way to install an auxiliary objective. If these buyers do not respond, don' t ask questions all the time, don' t cause unnecessary harassment to these buyers. Thank you! Attention: If you need M42 thread auxiliary objective lens, please click here. Specification: Wide Field Eyepiece: WF15X Objective Lens: 2X and 4X Total Magnification: 30X and 60X Working Distance of objective lens: 2X- 81mm(3.19"), 4X- 57mm(2.24") Working distance means the distance between the objective lens and the object when the focus is clear! Please pay attention on this! Please kindly note: The distance between the black objective lens cover and the stage is about 53mm! If you need 81mm working distance, please take away the black objective lens cover ! Articulated Free Binocular Head Diopter Adjustment: +/-5dp Interpupillary Distance: 55- 75mm(2.17"-2.95"), 45 degree Inclined Natural Light for Illuminating Gathered By ?60mm Black and White Reversible Stage Plate Power Supply: No Rack and Pinion Coarse Focusing Mechanism With Slip Clutch and Tension Adjustment Net Weight: 1.6KG Accessories: A pair of eye-caps, a pair of clips and a dust cover Inner packing: Foamed plastic + inner carton ? Please note this item hasn' t illumination. If you want to get LED ring lamp, you can buy via our store. : ) Pictures The pictures are for reference only, the actual eyepieces are WF15X