Brian O.wrote a review of Snow Peak Spare Lantern Mantles on May 17, 2012
These mantles fit the Snow Peak and Primus backpacking lanterns just fine, and they were the best price I could find right here. Well done, Backcountry!
One point--you are getting a three pack of mantles which I don't think it says directly on this page other than on the photo.
Primus has a great video on their site of how to put the mantle on and burn it for the first time. A tiny amount of gas and a slow burn off and I got a perfect sphere for a mantle.