You are expected to carry your own day pack, which should be able to sustain you until you reach a camp at the end of the day. You do not need to carry your person back-pack/ duffel-pack it will be carried by a porter. The weight per porter is limited to 20kgs. Your duffel bag will be brought from campsite to campsite-before you arrive it will already be there. What do you need during the day in your pack will depend on your priorities, but will generally include drinking water, basic medical kit, camera, water proof layers, a pair of gloves and hat, a warm layer, and snacks.