Sir/Ms:

We are Fuzhou Zhongtuo Optoelectronic Co.,Ltd. we are professional manufacturer of Gem refractometer

We have 5 kinds of this Gem refractometer and Digital Gem refractometer Beautifully designed and accurately measured. Buy 100 units and get 3 units free ,good quality and competitive price.they are your best choice.

If you need,pls remenber me!

Best Regards

General manager

Martin