This company is awesome. I got the large electronic dog door, and will never go back to a regular dog door. My pups can go in and out as they please, and I get the security of knowing that random wildlife or people cannot come in through the door. I've had the door for over 6 months and the collars work well. I can also control the door through an iphone app, so when I hear my dog running down the stairs (meaning she has found something she wants to drag outside to chew up), I open that app and turn off the inside sensor, preventing her escape. There was also a malfunction of a part in the door a few days ago, so the manufacturer is sending a brand new replacement door (even though a single part could be replaced), and Dog Door Guy is going to install the new door for me, free of charge. Initial installation process was seamless from the beginning, they managed to beautifully install the dog door in my unusual home door (and also fixed my door knob that barely worked! lol, thanks so much), and this customer service follow up is perfect. These are good people working at a great company. Couldn't ask for more, and very impressed. Highly recommend.