Manik Engineers LIQUID EYE gives simple indication of actual liquid levels in industrial and commercialrefrigeration systems. When liquid refrigerant is present the distinctive reflex glass appears dark; when vaporrefrigerant is present, the glass is light. The long neck housing provides enough length for ease of welding andinsulation clearance for low temperature applications. The optional frost-free shield facilitates clear viewing ofrefrigerant level under frosting conditions.The Liquid Eye is available in 2 types :1. MLE - Which can be directly welded upon pressure vessels or liquid columns2. DMLE - Which has dual glass for viewing the internal media and is mounted inline.