Stanley vacuum 8111007W wet dry filter. Will fit other model also. Fit without a cap less leakage.

Stanley 08-2501 fit 5-18 gallon

SL18115, SL18115P, SL18116, SL18116P, SL18191P, SL18199P, SL18117, SL18701P-10A, SL18410P-5A