The top roller installed at the both sides of the tin bath can effectively control the width and thickness of the gross glass ribbon. The main technical index: The thickness of glass sheet:1.0-25mm The horizontal oscillative angle of head: ±19℃ The accuracy of head's oscillative angle: ±0.1℃ The speed of rotating coil of head: 10-1500m/h The accuracy of coil-speed of head: ±0.01% The radial direction run-out should be no more than 0.2mm The accuracy of head's pressed-depth: ±0.1mm The biggest depth for head (inside the bath): 2000mm The longest distance of machine frame for lifting up and down: 100mm The accuracy of machine frame for lifting up and down: ±0.1mm All the above index can be customer-designed.