- Quality Assurance: All submersible pumps have passed CE, ROHS international certification. 2. Quiet design: the introduction of German quiet technology, low noise, optimized submersible pump components, to achieve noiseless, low noise working pump. 3. durable and waterproof: good insulation, high temperature and wear resistance, long service life. 4. Ceramic rotor: more wear resistant than stainless steel rotor, more energy efficient and quieter. 5. Strong fixed suction cup: suction cup design, superior suction force, no hardening, long service life.