Hi all, I’m in the market for a day pack which has a capacity of 20-23 litres or so, and some requirements I have is that it has to have a clamshell style opening for the main compartment, as well as ventilation on the back and also has an internal stiff board. Other details would be nice but those three are the main requirements. Always prefer quality hardware if possible (ykk, duraflex), thanks in advance!