Shanggui answer your question here:

The Qinhuangdao Shanggui's solar panel has got ISO 9001 and our junction box passed TUV.

Photovoltaic projects rely on high quality products that stand the test of time for inputs ranging from engineering design to financing and more. Shanggui Solar’s products have always maintained high reliability and solid performance based on our commitment to our quality-first policy. In our upstream business model, we tightly control quality over every step of the manufacturing process, from silicon crystallization to module deployment in the field. Shanggui guarantee the quality of our products with an industry-leading 25-year lifetime warranty.