Feature 1.High durability and reliablility Excellently high durability than others using bigger diaphragms in diameter. New exterior air valve system shuts out air switching trouble (pump stop). 2. Maintenance free No packing is used for sealing, therefore, no paint leakage by packing wear. 3. Easier washing and color-changing Pump structure is so simply designed to be easy to flush, fast color change, and easy to disassemble for maintenance.