That's a knock off of the old Sierra saw which has been around forever/i have this one and can give it a thumbs up for small stuff:
you can always remove the frame and make a bigger 1 it be harder to use but you can just add a saw blade and make a frame for it..I have never used one of these, but I have used other bow saws over the years. Bow saws tend to bind easily, this can lead to breaking the blade. These days I just carry a small cross cut saw. A Stanley Fine Finish saw. It comes with a great blade cover, and is very light because of a plastic handle. I got it at Menards for $8.
Last summer I brought it on a canoe trip. My buddies daughters thought it was funny when I started cutting down a dead tree about 14" in diameter. 20 min later it crashed down and they were impressed to have all kinds of firewood right next to camp. They had been foraging deep into the mosquito infested forest. I could not have accomplished this with a small bow saw because the frame would have stopped me from cutting deep enough.