Promotionally priced 20-piece magnfier set. 3 Magnifications;150x, 450x, and up to an enormous 900x power. 20 pieces- Includes 5 prepared, 7 blank glass slides, interchangeable eyepieces, beakers, dye and hard shell carry case. Large easy-turn rotary focusing knob and high-quality Vivitar optics. Educational, fun at the same tim and high-quality. Great for science projects, school science lab and exploration.