Ideal for ordinary and advanced level biology studies. The Zenith 'Ultra-400' series are purpose built teaching instruments finished to a very high standard, combining excellent optical performance and a very reliable, modern, user-friendly design with a mechanical construction designed to withstand the rigours of everyday heavy classroom use. All models feature high quality DIN standard optics, 'Anti-tamper' safety features include locked-on eyepiece and stage clips, slip-clutch on the coarse focus movement to prevent over-focussing and an adjustable focus-stop to prevent damage to glass microslides and objective lenses. Highly Recommended