The Thunder 50 and 70 packs were specifically designed to be very light in weight but capable of handling loads of over 50 lbs. In preliminary testing we were pleasantly surprised at both the comfort and load carrying capacity of the T-Rex frame system. The Exped Lightning 45 and 60 also use the T-Rex frame and are even lighter than the 50. While there are lighter packs on the market, none have the carrying capacity of the Thunder and Lightning series packs. 

Click here for the full review.