Did a quick search and didn't get any hits, apologies if this is a repost.
http://nb-wonderbag.com/
Its the same principle as haybox ovens, except it used polystyrene balls as the insulation material
[video=youtube_share;FnHtmRSNV48]http://youtu.be/FnHtmRSNV48[/video]
http://nb-wonderbag.com/
Its the same principle as haybox ovens, except it used polystyrene balls as the insulation material
[video=youtube_share;FnHtmRSNV48]http://youtu.be/FnHtmRSNV48[/video]