I use these every summer. I have 3 lanterns and 1 rounder one. They have always worked great. They are a little bit "pricey' - but worth it! And customer service is amazing!!! They care about their customers.
Your thermacell is not going to keep working without additional butane cartridges and mats. The original refills are great for concerts, picnics, backyard activities, etc. as a single mat will give you 4 hrs of protection. The MaxLife refills, with their 12 hrs of continuous protection, are perfect for that camping trip so you can insert one pad at sundown and still be covered in the morning when getting up to make coffee.