Can someone explain Tropic Marin hydrometer chart?

Buy Tropic Marin High Precision Hydrometer - Tropic Marin at the best price of CAD $ 44.99 at BIGShow Frags

High Precision Hydrometer - Tropic Marin

5596 - Tropic Marin High Precision Hydrometer

6242 - Tropic Marin Bio-Actif Sea Salt 25kg/750l - Bucket

media2.cdn./media/magefan_blog/m

Temperature Corrections for Hydrometers by Randy Holmes-Farley

Can someone explain Tropic Marin hydrometer chart?

Tropic Marin HIGH PRECISION HYDROMETER, claim's it's super accurate and never needs calibrated., Page 2

Don't GUESS on Your Reef Tank's Salinity! Tropic Marin Hydrometer

Tropic Marin Kh/Alkalinity Test Kit for Freshwater & Saltwater Aquariums