Instructions for use:1. Confirm the glass thickness to select the glass cutter head suitable for the cutting range.2. Wipe the glass surface to make it smooth and clean.3. Inject lubricating oil into the glass cutter handle and confirm overflow from the blade roller.4. In the process of cutting glass, the cutter should be fastened to the ruler and parallel to the ruler movement. Curve cutting should be done well in advance.5. After cutting, the glass should be broken open or folded.Precautions:1. Do not use woolly glass and non-smooth glass.2. The glass thickness should be selected to select the corresponding glass cutter model and reasonable use of pressure.3. It is best to add kerosene or other oil to the handle before use.4. The pressure during cutting is not too heavy or too light, 20n is suitable5. While cutting a straight line, the cutter head should be close to the ruler.6. When cutting the glass curve, it is better to do with a curve gauge.7. In the process of cutting glass, you only need to hear the crisp cutting sound; Crossing the line must not be repeated, otherwise, the cutter wheel is easy to damage.8. It is recommended to drip a small amount of oil into the working part of the cutter wheel and axle to make the anti-rust and maintenance wheelSize Chart:Length: 12 cm / 4.72 inchHead : 2.5cm/ 0.98 inchPackage Includes:1* Glass Cutter