So far I haven't found a number either stamped or printed on filter, I tried the 51006 again and just succeeded in getting it stuck and ruined it getting it back out. Maybe in the light of day after it drains overnight I will find a number. both of the gaskets supplied with the 51006 are too large for the top of canister. Every site I've been to recomends the 51006, it's eqivelant or something larger.
