What are these l brackets for

[New chicken]

Hi, I am just wondering if anyone has used this door for the go up and how it works , does it have a way to close the door during the time it's set to be open. Thanks 

[Fletch224]

I have one and its brilliant! It works on a light sensor, so wont close until its dark,.....opens next morning when it gets light, although there is a way to get it to open at a time that suits you. I love it to be honest

[New chicken]

Thanks for the reply, I decided to go for one and it has been great, when I got my chickens they stayed in the coop for a day on their own will but when they came out they knew when and where to go back in and they have never missed a night so far. I'm very happy with it. I had an issue with the bolts to hold the gray plastic onto of the gears but I just used longer bolts and let them know about it. I only whish that the wi fi pick up was a bit better as I can't get WiFi on it where my coop sits but I can on other devices over at the coop. Thanks