Instruct: Classify Amazon reviews into positive or negative sentiment
Query: this thing is great buuuut.....

attaching the canister to the heating unit is a monumental task i could not do it at all and especially because i am disabled with use of only 1 hand. attaching the canister is the only camplaint i have about this product it is impossible for someone like me to do it i also had each of ,y 2 brothers try and they had the same problem,...perfectly able bodied guys couldnt get the cannister attached...should be simple:depress locking feature,innsert canister,release locking mechanism and bobs your uncle! nope...not quite...on the side of the thing it looks simple but me nor either of my brothers have gotten it attached correctly...we can get it attached ,however, it is crooked everytime (and it must be straight for it to work properly). this product is useless if you cant get the canister of gel attached...i feel totally ripped off!