The Waterway Viper is a high volume pump that has an increased flow rate compared to the Waterway Executive 56 because of its 2.5" Intake and 2.5" discharge. Comparable to the Gecko XP3 Series Pump. It is best to always replace your pump with one that is the same or close to what you have. If you have any questions please contact us. Waterway as of Sept 2024 has changed their supplier of motors therefore the SKU number has changed but the pump is still a Waterway Viper #3721521-1V
