Four objectives with 4x, 10x, 40x, 100xs magnification. You can use these objectives for classic "dry" observations; also, a 100x objective allows for observations using oil immersion. 40x and 100x models are spring-loaded. A 0.17 mm cover glass is required for observations. Levenhuk MED 1000 Plan Objectives Set, 4x, 10x, 40xs, 100xs (oil) is compatible with MED 1000 Microscopes. These infinity corrected objectives improve color rendering, minimize spherical aberrations, and correct up to 95% field curvature across an image diameter. These plan objectives are ideal for professional microbiological research.