Generic 2 in 1 Light Source Gem Refractometer

Gemological Refractometer with 2 in 1 Light Source Built-in LED Light or External Light Source flashlight .
Used this to measure Refractive index of Gemstone or Ore, index of double refraction and identify authenticate polished precious and semiprecious gemstones as well as observing the optical properties and the structure of gemstones, transparency or opacity and its beauty, durability and scarcity.
Features:
NEW DESIGN
2 in 1 Light Source: Built-in LED Light + External Light Source (flashlight)
Convenient & easy to carry
Built-in LED illumination
FREE Index Fluid and small flashlight/torch
Built-in Light Source Filter for outside light source
Approved by strict quality and safety standards
Undoubtedly durable and very reliable
Characterized by small volume and less weight
A popular instrument used on jewelry market

Specifications:
Filter: Polarizing filter
Measuring Range : 1.30 - 1.81 RI
Minimum Graduation : 0.01 RI
Accuracy : ±0.02 RI
Illumination : Internal LED Light Source with momentary/power switch
Power: 1.5V Button Batteries (3pcs)
Dimension : 30 x 70 x 130mm
Weight : 400g
Ranges of Application: Laboratory, Gemology

Set includes:
1 x Gem Refractometer (New Design)
1 x Vial of 1.800 Refractive Index Oil (FREE)
1 x Flashligt/Torch (FREE)
1 x Polarizing Filter
3 x 1.5V Button Batteries (FREE)
1 x Cleaning cloth (FREE)
1 x Reference Block (FREE)
1 x Hard carrying/storage case
English User's Manual