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

Input:
Question: how thick a wall can it be installed on? Are there extension kits?
Document: Installed an LP version in small trailer house last week. Great heater, easy installation with simple instructions. Very safe operation and seems very efficient. Unit is cool around and below and beside - - and warm on top. Nothing scary straight above heater, just warm air in front of top. Will buy an NG version for my home. I recommend this heater to anyone. I wish I could find the smaller one also.
I am thrilled with the well made simple design and this efficient, stream lined, VENTED unit. The heat producing area is enclosed to provide protection from unintended contactg with the HOT metal areas. And, sincne it is wall mounted and OFF THE FLOOR - the hear rises and circulates easily, and is NOT an attraction for furry friends wanting to get too close. I recommend using a licensed GAS plumber for install - it is cost effective to run and works VERY well.
Works great. Had a key part missing but was able to buy a replacement (luckily) at my local hardware store. Overall good heater
We have purchased 6 or 7 of these heaters for our employee housing. ( Me included), and love them. The look good, take up limited space, give up great heat and are resonably priced.3 of the heaters came with shipping damage. The boxing is marginal and needs improvement.
We have a heat pump but need backup heating on really cold days. Purchased 2 of these and have used them all winter. Very pleased. But packing was filmsy and did have to order some replacements parts when we got them. Customer service was very good and new parts was in very heavy cardboard and perfect condition. Was really glad we had these because of especially cold winter and wood burning stove we were using was a lot of work!
Rather than returning this heater when it came with sheet metal bent up,  (could not tell until box was opened) I took the shroud to a body shop and they straightened it out for 50$. Heater now works and looks great.
Came like the picture and worked as discribed, would have give a 5star but did not heat as well without a blower to spread the heat.
Answer: no