Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A mediocre product.

The temperature of this heater varies from toasty warm to barely lukewarm for no apparent reason relating to fuel level or ambient temperature. The catalytic cap fits so precariously on the body I suspect that variation in heat transfer between the cap and body is the reason. The slightest bump will cause the catalytic cap to pop off, regardless of how hard it has been pressed on. All in all this is not a dependable device.