Important reminder: 1. The glass wiper must move forward, don't go back , and the moving speed is uniform. 2. Selection Guide A. The magnetic force cannot be adjusted 3-8mm:Use for the thinnest glass window, bathroom glass 15-30mm:Use for single-layer or double-layer glass, thickness must be greater than 10mm---can be used in high-rise buildings B. Magnetic force can be adjusted 5-25mm: Use for thick single-layer glass, thickness must be less than 20mm --courtyard-style home use 5-30mm: Use for single-layer or double-layer glass, thickness must be less than 30mm--can be used in high-rise buildings 5-35mm: Use for single-layer or double-layer glass,thickness must be less than 35mm --can be used in high-rise buildings 10-40mm: Use for single-layer or double-layer or triple-layer glass. thickness must be greater than 10mm but less than 40mm--can be used in high-rise buildings Best choose the glass wiper that exceeds its magnetic range according to the thickness of the glass! How to use it? 1.Keep the safety rope in hand first. 2.Turn the glass rub open. 3. Soaked in water to allow the sponge to absorb moisture. 4. Add a little cleaner to the fiber cloth. 5. Align the glass rub, natural adsorption 6.Start to wipe glass. 7.If the attraction is not enough, you can turn the knob to adjust the magnetic force, until the two magnets are attracted closely, but can easily move on the glass. 8. If you feel that the two magnets are too attractive to move on the glass, you need to rotate the inner magnet to the right until the two magnets are separated, and then turn the adjustment knob again to adjust the magnetic force Feel free to ask our customer service any questions you may have.It's made with ABS material, Natural Latex, NdFeB magnet of premium quality to provide strong magnetic force. This Magnetic Glass Cleaner Wiper is effective for Smaller thickness double glazing, glass door, bathroom glass, indoor glass wall. It comes with 2m long safe anti-falling rope, when use it, the rope will be tied to your hand, open window and attach the half wiper on outside window, attach the other half inside window, Prevents magnets falling to the ground to hurt pedestrians, provide you a stable and safe cleaning experience. If you feel that the two magnets are too attractive to move on the glass, you need to rotate the inner magnet to the right until the two magnets are separated. At this time, the magnetism will return to the minimum, and then turn the adjustment knob again to adjust the magnetic force. It can easily wipe the corners, magnet locking the two cleaning sides together, When you move one side, the other one follows. you can adjust the strength of the magnetic force to suit the thickness of the glass, If the attraction is not enough, you can turn the knob to adjust the magnetic force until the two magnets are attracted closely, but can easily move on the glass. This magnetic glass wiper is effective for courtyard-style home use Single Glazed or Double Glazed Windows thickness. the interval of double-layer glass must be less than 25mm. when use it, it must move forward, don't go back , and the moving speed is uniform.