Features:

This Classic hydrometer is an affordable measuring device for marine tanks.
It is a economical way to determine salinity.
This device is a must have for all marine enthusiasts.
It is easy to use and salinity result can be known instantly.

Specifications:
Size: 16 x 7.8 x 1.5 cm
Accuracy up to 0.001, do sampling test at about 5cm below the surface.
Note: When the water temperature is at 20-30 degrees, the measurement is the most accurate.
Be sure to wash and clean the hydrometer with clean water after use. If there is salt attached to the pointer, it will affect the accuracy of readings. If there is salt crystallization in the hydrometer, after soak it in weak acid for 30 minutes, wash and clean it with clean water.
If there are bubbles attached to the pointer, it will affect the accuracy of readings. Please check carefully before the test whether there are air bubbles attached to the pointer. If there are bubbles attached to the pointer, gently tap the hydrometer to eliminate air bubbles.