The K2-1157SW-C3SB-04 tactile switch is a surface-mount-device (SMD) push-button switch manufactured by HRO Parts. It is RoHS certified, indicating that it has lower levels of hazardous materials, such as lead, compared to non-RoHS components. The switch is a momentary, normally-open (NO) type, and useful for control circuits in low power applications. It has an operating temperature of -20°C to +80°C, and its contact material is silver-plated nickel. It has an electrical life of 50,000 cycles, and a maximum contact resistance of 500mO. The switch has a suitable tactile feel, with an actuation force of 200gf.