精品一区二区AV天堂色综合|久久影音第一页午夜|亚洲成AV人久久|无人区乱码一区二区三区

The utility model increases the spring elasticity to reduce the electromagnet power by means of the connecting rod principle, has the advantages of energy saving, fast start-up, and the brake assembly is novel in conception and reasonable in structure, and has the advantages of fast braking speed, good braking effect and long service life. Can be widely used in a variety of electric lifting doors and windows, shading systems, projection screens and other products.