Features: This module uses MCU as the main chip. High timer precision. MCU watchdog circuit and special reset chip. Stable and reliable work. Specification: T1(the relay turn on delay time), T2(the relay turn off delay time) Once mode (Jumper OP3) 1. The module Power-on, When triggered the relay is switched on, delay T1, and the relay disconneted. 2. When triggered on the delay process, again triggered, it will immediately interrupt the delay. Cycle mode(Jumper OP4) 1. The module Power-on, When triggered the relay is switched on, delay T1,and the relay is disconneted, delay T2, the relay is switched on again. Such cycle. T1 and T2 are set by two adjustable resistors, respectively. 2. When triggered on the delay process, again triggered, it will immediately interrupt the delay. Typical application reference: 1. timer operating equipment, such as each press key trigger,when reach 5 minutes the automatic power off. 2. machine repeat test circuits, such as power 1 minutes on and then power off 1 minutes of ,such a cycle of testing. 3. fish tank pump intermittent pumping oxygen. 4. other timer control equipment. Performance: Jumper OP1: 1 to 100 seconds, 0.1 seconds of regulation accuracy Jumper OP2: 1 seconds to 15 minutes, 1 seconds of regulation accuracy The time delay error of all kinds of temperature and humidity is not more than 2% Size: 7x2cm/2.76x0.79inch Quantity: 1 Pc Note: Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Contents: 1 x Infinite Cycle Delay Timer Relay