This special feature provides greater clearance between the microscope and the viewing object. Dino-Lite models with the LWD feature cover a lower magnification range and larger depth of field than standard models. The magnification range for Dino-Lite Edge LWD models is 10x to 140x (14:1 zoom ratio) with working distance greater than 3cm. The magnification range for Dino-Lite Premier LWD models is 20x to 90x (4.5:1 zoom ratio) with working distance greater than 5cm.