س: ما هي الوظيفة المحددة للضوء الأحمر؟ لماذا لا يتوفر في طراز USB؟

ج:

The red light uses a low-energy 650nm wavelength, which can penetrate the skin surface by 1-2mm, stimulate the activity of cell mitochondria, and accelerate tissue repair. It is especially suitable for long-term repetitive strain. The USB model, being an entry-level product, has not been equipped with a red light module for the time being to control costs and size.