Common features include fully insulated interiors and multi-layer thermal systems (often three-layer) with PEVA or aluminized waterproof/thermal liners. Some products add antimicrobial or leak-resistant inner liners to help keep food fresh and reduce odors.
Kits may include utensils (spoon and fork), a food container or divided tray, and occasionally a small separate container (for example, a 2-cup container) or a removable tray/divider.
Bento-style boxes often use leakproof or leak-resistant lids and contoured seals to reduce spills. Soft bags commonly feature leak-resistant or waterproof interior liners to limit messes inside the bag.