男ji大巴进入女人的视频66m,欧美疯狂做爰3xxx高清,小雪尝禁果又粗又大的视频,爱爱的故事

                

 
Product Introduction:
■ Easy to use and portable
■ low price with long lifetime
■ can be used to detect many defects, like micro crack, bubbles,  impurity, crystal subgrain
■ When the laser go though the crystal, if it is monocrystal the light should be scattering, in macro it should be white.
■ If there is bubble, the light also be scattering, but in macro there will be white spots.
■ The cracks can be easily observed.
■ With the laser light you can find the impurity easily.
 






 
Polarized glasses:
Use Oil of wintergreen to wipe the C-axis surface of the sapphire crystal ingot, and use polarized glasses you will see the concentric interference rings on the ingot surface.
 




 
Customer:
American, Europe, Asian sapphire manufacturers.