Buyers should prioritize the IP (Ingress Protection) Rating capability, specifically ensuring the machine can perform tests from IPX1 to IPX6 (drip, spray, and jet) or IPX9K (high-pressure steam jet) depending on the target industry. Key components include a stainless steel (SUS304) interior to prevent corrosion, a high-precision flow meter, and a rotating turntable with adjustable speed to ensure 360-degree water exposure. Additionally, verify the nozzle diameter accuracy and the PLC control system for automated testing cycles.