These microscopes feature a reversed nosepiece to facilitate easy slide changes. The 40XR and 100XR objectives are retractable and spring-loaded to prevent damage to slides and objectives when focusing. They are also sealed to protect against further damage that can be caused from contact with liquid or oils. Rack and pinion adjustable 1.25 N.A. Abbe Condenser, and turn-wheel opening iris diaphragm with plastic shield protector, for optimal resolution and image contrasting. Brightfield LED illumination illuminates the specimen from below, making the specimen appear bright, but much darker than the bright background. Rugged cast aluminum with grey enamel finish. Packed in a fitted Styrofoam box and includes a dust cover and instruction manual. 5-year limited warranty excluding bulbs.