... ;4,super-hard alloy seal, has longer lifetime;5,special structure design, its flow is much larger than similar pumps;(Example: 50mm ... ;4,super-hard alloy seal, has longer lifetime;5,special structure design, its flow is much larger than similar pumps;(Example: 50mm ... 550 ~ 600L / min)6,water cooling and sealing anti-noise design, almost no noise, quiet environment. Amphibious self-priming pump,bellows ...