The Trane A2140 (SWT1258, C340056P02) is a limit switch/thermostat disc assembly designed to monitor and control temperatures in HVAC systems. Featuring an auto reset mechanism and a 3" insertion length, this switch reliably opens at 170F and closes at 140F, providing dependable over-temperature protection for furnaces and air handlers. Key Features Auto reset functionality for seamless system protection Temperature range: opens at 170F / closes at 140F 3" insert for deep sensor penetration and accuracy Helps prevent overheating and improves equipment lifespan OEM quality for precise and consistent operation Specifications Part Numbers: A2140, SWT1258, C340056P02 Function: Limit Switch / Thermostat Reset Type: Auto Temperature Rating: 140F close / 170F open Insertion Length: 3 inches Type: Disc-style thermostat Mounting: Standard HVAC bracket fitment Compatible Models Model list not provided. Please share model compatibility if available, or refer to Trane documentation for application specifics. Why Choose This Item Choose the Trane A2140 thermostat switch for safe and automatic thermal regulation in your HVAC system. Its OEM design ensures compatibility and reliability, while the auto-reset capability minimizes downtime. It's the smart choice for professionals looking to maintain system performance and safety with trusted Trane quality.