Buyers should prioritize load-bearing capacity, typically requiring a minimum of 150kg (330 lbs) to ensure user safety. For portable flushing models, look for high-density polyethylene (HDPE) construction, which offers superior durability and UV resistance. The sealing mechanism is critical; ensure the unit features a double-sealed drain valve to prevent leaks and odors during transport. Additionally, check the waste tank capacity, usually ranging from 10L to 20L, to match the intended usage duration of your target market.