Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: Do you have to buy the extension, or can you use the one from your old opener?
Document: NOTICE: opener rail (If real not strong enough) will broken when use on old one piece door without track even you have the powerfull opener head.
Excellent product. Just as I expected. I took out the old Garage Door Opener and installed this one instead. The whole project took about 3 hours. I also programmed my cars and the key chain to open the door.I definitely recommend anyone to buy this product.Shipping was also VERY FAST, so excellent experience and great value.
The instructions were easy to follow and had the opener up and running in a very reasonable time. By the time I dismantled the old opener, put this one together and installed it was about 3 hours. Works better than what I had and is very quiet. Only problem was that I cannot use my old keypad on the outside of garage to operate this opener, so I had to order that. The package came on time. Would recommend this opener to others.
If you have a higher door, you'll need the extension kit.Some have said this unit requires you to be in your driveway to use it. Well, I paid special attention to the antenna, making sure it was extended down from the unit straight. Anyway, my remote works from several houses away, so there's no distance issue with it. We have an aluminum garage door, so maybe it's worse with certain door types, but it's not the unit.The motor unit itself is very quiet.
One month old , working great on a very heavy 2-car garage door. Seems to lift it effortlessly so far.. Old 1/2 hp Liftmaster lasted 9 yrs with light use. Could not use old center rail due to redesign to  half cable half chain. I did reuse old sensors and brackets . New brackets were not adjustable for length. I will just store new ones for later. Bought through Amazon because local store only stocked one model.
It's a great product and get the 3/4 HP model. Took a little effort to install. There are a few tricks installing this.1. Need more and stronger mounting brackets. I had to buy a few from Home Depot and cut them to fit.2. Need more lag screws to go with the brackets.3. Had to buy an automatic Garage Door Closer from Amazon (Xceltronix)4. Use levels and triangle to make sure things are level and plumb.
Use this to reference where to attach a hanging bracket across the ceiling. Make sure the ceiling bracket is screwed into a ceiling joist on both ends (before you start buy some 2 to 3 inch lag bolts and a sturdy ceiling bracket, neither are included)  Then you can use bailing wire or a clothes hanger to hang the motor end and have both hands free to connect the supplied hanging brackets.The slowest part was mounting the Safety Reversing Sensors and then running the wires.
Installation no problem, works fine, replaced a 10 year old model with stripped gears. BUT, the new opener and remotes are not compatible with existing remotes for my other Chamberlain garage door opener (about 5 years old) and the overhead console remote in my Yukon. Very annoying. Of course, I can buy a converter to adapt the old to the new, but then I will need additional openers also, and still wont work with Yukon remote!
Product works Great! Replaced a 15 year old opener, it works flawlessly! Installation was quick and Chamberlain support is great. Had to use them on the door sensor install, very helpful and very quick. Door opener functions great and would recommend this opener to anyone.
I looked around and did some research and decided to buy the Chamberlain.The installation was very easy since I used some of the hardware from my old door opener, even though I really took my time (total of 6 hours)and installed it by myself. Instructions were written out very clearly so you cannot get confused. I had this new opener for 3 months and its performance is outstanding, it is very quiet and lifts the door without any problems although the door is all wood and is very heavy.
Answer: yes