Ideal for higher magnification microscopy, the BRESSER 40x DIN Plan Achromatic Objective Lens produces flat and even fields of view from edge to edge with little or no spherical aberration visible. The lens is spring loaded to absorb the impact and pressure in case it comes into contact with your slide or specimen to protect the objective and your specimen. It is parfocal with other 45mm length objectives, so there will be little or no focus adjustment required when changing magnifications. To make it easier to identify the magnification during use, the barrel is color coded blue.