1. Actuator (Toggle Head) Coating/Material: This constitutes the sole core difference between the two models. The "L" in the model number typically denotes a standard plastic material, while the "T" indicates a coating of Teflon (PTFE). 2. Chemical Resistance and Durability: The Teflon coating provides superior resistance to solvents, oils, and most chemical agents, coupled with a lower coefficient of friction. In environments prone to chemical contamination or requiring frequent operation, the M2122TCFW01's toggle surface is significantly more resistant to degradation and wear, while maintaining a smoother actuation feel. 3. Application Preference: The M2122LCFW01 (standard type) is suitable for general, clean electrical control environments. The M2122TCFW01 (Teflon-coated type) is better suited for industrial settings, laboratories, medical equipment, or other complex environments where potential exposure to factors like hand perspiration, cleaning agents, or lubricant splatter could adversely affect standard plastics. Additional Note: Both models share identical electrical specifications (voltage, current, mechanical life), mounting dimensions, and illumination parameters. Therefore, substitution is seamless from both an electrical and physical installation perspective. The decision hinges solely on the requirements for the actuator's surface characteristics.