Fiber Laser Machine Lenses Based on the lens, the working area is determined. 70mm×70mm lens means 7 centimeters. 110mm×110mm lens means 11 centimeters. 150mm×150mm lens means 15 centimeters. 200mm×200mm lens means 20 centimeters. 300mm×300mm lens means 30 centimeters. Changing the lens changes the working area.