Our full selection of microscope objectives can be used with all major brands of microscopes. Our matrix includes both DIN (Deutsches Institut fÃ¼r Normung) 45mm standard and JIS (Japan Industrial Standards) 36mm standard objectives. All optics are AR coated. DIN microscopes are configured for a 160mm tube length, and JIS microscopes for a 170mm tube length. DIN and JIS objectives can be interchanged, although the powers will not be equivalent (approximately 10% difference). All 20X to 100X objectives have spring-loaded (retractable) front ends in order to prevent slide damage. Oil immersion is recommended for all 100X objectives in order to achieve an NA higher than 1.0 (for typical use: low viscosity 150 cps, 0.5 oz. tube with nd=1.515).