Instant Ocean HydrometerInstant Ocean Hydrometer is accurate, reliable water test equipment is absolutely vital to creating and sustaining a healthy, successful marine environment. Accurate to 0 001 Durable, Permanent Needle Mount Easy Read, 2 Color Scale with Safe Zone Extra Wide Stabilizer Base Easy Fill convenience NO WET HANDS! Easy to read and simple to operate, the Instant Ocean Hydrometer delivers precise full range salinity and specific gravity readings accurate to