The ABB 2TLA020006R2100 JSHD4-1 Top Part is an essential component of the JSHD4 three-position device, designed for enhanced safety during machine operation in hazardous areas. This top part is compatible with bottom parts AB, AD, AH, AJ, AK, and AL, providing flexibility in configuration. It features a straightforward design with no LEDs or extra buttons, ensuring ease of use. The anti-tamper option is available for all bottom parts except AK, offering additional security. Ideal for troubleshooting, test running, and programming, this device allows limited machine movement, ensuring operator safety in dangerous environments.