This product has a Lithium-ion battery. Will not mix with sound squander stream. Spent batteries really should be disposed of by a certified recycler or harmful resources handler for every area regulations. trong m?t kho?n th?i gian nh?t ??nh tr??c khi ?i?u ch?nh, t?t nh?t b?n nên dùng ph??ng pháp t? ??ng ho?c xây d?ng hàm ?? ki?m tra v?i d?