Brymill 502 Fixed Withdrawal Device, use with 20L Dewar made after 2007Device is attached to the top of the 20L dewar (only works on those made after 2007) and remains in place. Simple on off controls work like a faucet and can fill multiple cryosurgical units at a time. Other sizes available for 30L and 50L dewars. Special order item, therefore it cannot be canceled once the order has been placed and is non returnable after it has been received. 1 year warranty