http://www.thermoldproducts.com/products.html
Don't personally have any experience with Thermold products (although I've heard them referred to on occasion as "Thermelts" or "Thermites"). Their website does make a point of mentioning the run-over-by-a-truck test which seems to borrow from Magpul's promo.
With such superior products such as the P-Mag and L-5 on the market nowadays, Thermold would appear to be somewhat of an afterthought in the polymer magazine arena. Are their products at all improved from the earlier offerings?
