Model Number Size, Gear Type & Ratio, Serew Type, Outdia, Lead, Bellows Yes or no, Stroke System SR 45 - 10 Servo Box Specification Servo Box Model SR45, 65, 75, 90, 110, 120, 150 Ratio Single Stage3, 4, 5, 6, 7, 8, 9, 10Double Stage15, 20, 25, 30, 35, 4050, 60, 70, 80, 90, 100