A pre-assembled disposable Bowie & Dick type test. Once-A-Day Test Pak is a pre-assembled disposable Bowie & Dick type test designed for daily monitoring of pre-vacuum sterilizers operated at 270-276F. Identical in challenge to the standard AAMI towel pack, Once-A-Day Test Pak guarantees detection of the residual air in sterilizers caused by air leakage, pump malfunctions and other technical problems.