Transmitter T4xxx has been designed for some time, recently finished bulk production. As a new one, hope it will be popularly welcomed by our dear customers. 

Usually, there is more or less interference between 2 sets of photocells when they work. In the past years, Hiland also faced this problem. Now our engineer has improved this and successfully make less interference between photocells. That is, we have enhance the anti-interference function of photocell. When one set of photocells works, another one are not that easily influenced. 

Hiland just do our best job in packing process to make our customers' goods protected. 

Usually, our tubular motor receivers are one set photocell(emitter and receiver) or two same type sets (both contactor or both impulse) connected, but, TM5820 can be connected with 2 sets of different photocells(either contactor or impulse).