The bolt and chamber adapter weigh about the same as a 5.56mm bolt. The op rod is 1/8" bent sheet metal, so its light. The recoil spring is lighter than the standard. So, yes, it would fit nicely in a backpack. The box it came in is heavier than the kit, so you would want to buy or make a bag to keep it in. There are enough small pieces that you don't want it loose. It only took me a couple of minutes to install it. Now that I have done it I could do it faster. You just take off your bolt, op rod, and recoil spring, install the chamber adaptor, an install the bolt, op rod , and recoil spring. Piece of cake.