From Coralife. Range is 1.000 to 1.032.

Every unit is calibrated and tested for accuracy using advanced testing procedures.

With its durable construction and easy-to-read scales, the Deep Six is guaranteed to provide years of reliable performance. Designed to give temperature-corrected readings in warm water aquariums, readings can be read in ppt and specific gravity. The Deep Six is accurate to +/- 0.001 specific gravity.