With just a screwdriver and a few minutes, General Pipe Cleaners’ Flood-Guard™ can prevent costly property damage and messy cleanup. Made in the U.S.A., Flood-Guard operates like a check valve to seal off water back-up caused by overloaded sewers. The float model is available for 2", 3" and 4" drains. Additionally, Flood-Guard comes in a standpipe model for extreme pressure that’s available for 3" and 4" drains.