The TS-1011S-A135B3-D2 is a tactile switch manufactured by Yuandi. It has a surface mount design and is 12 millimeters by 12 millimeters by 10.5 millimeters. It is compliant with RoHS standards, meaning it is safe for human health and the environment, and is lead-free. The switch is made up of four individual contacts (normally open (NO), normally closed (NC) and two common terminals. The switch has a minimum travel of 0.2 mm and an operating force of 140 grams. There is a contact resistance of 500 mO, and a rated voltage of 50 VAC. The rated current is 100mA and the insulation resistance is 100MO. The switch is designed for applications where a tactile feedback is desired, and is appropriate for use in consumer electronics, pro audio, industrial machinery, telecommunications, and medical equipment.