Cap for BOD Bottles-WTN 227723

A polyethylene cap complete with a closed cell foam insert snaps firmly over the flared mouth of WHEATON BOD bottles to prevent evaporation of the water seal during the five-day incubation period. The foam insert is specially designed to fit into the cap and exert pressure on the stopper to hold it securely in place. It will not absorb or leak water if bottle is tilted. 50/cs.