Encoders Rotary Encorder Hollow Encoder Series Picture Size Shaft Operating Direction Resistor Elements Switch Option Rotational Angle F1001E 14.5mm / Side / Push 360° F11E 11mm Metal Up,Side / N/A,Push 360° F12E 12mm Plastic Up,Side / N/A,Push 360° Series Picture Size Shaft Operating Direction Resistor Elements Switch Option Rotational Angle F20E 20mm / Up / N/A 360° F28E 28mm / Up / N/A 360°