Model Number A3--20PCS: This timer switch is designed with a robust plastic material ensuring durability and reliability in various farm animal applications, suitable for continuous usage in demanding environments. hengjiumande: Renowned for quality, our offers in automation technology, ensuring that this timer switch operates with high efficiency and accuracy, ideal for managing time-sensitive tasks in agricultural settings. Battery Requirement: Note that this model does not include a battery, allowing you more flexibility in choosing a compatible power source that best fits the operational demands of your farm environment. Chemical Safety: Free from high-concern chemicals, this timer switch is safe for use in environments with farm animals, ensuring that their health and the ecosystem remain protected. hengjiumande Official Store Color: As Shown Material: plastic Package Contents: 2*Switch Turn On Off Relay Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.