I don't think the other lid is removable. I've never been able to get it off at least. I like unicolor unidrums for 4x5 development, except that my very worn tank has a very worn gasket (the grey plastic disc inside the lid..). It leaks a lot. I've tried everything except cut a new gasket. Silicone sealant (don't try it), lightly heating it with a heat gun and stretching it (don't try it) etc. I just need to get a new drum. A good thing to do if you have some silicone lubricant spray, is to spray the outside top of the drum, inside of the lid and gasket. Makes getting the top on and off a lot easier. Also, two of the widest rubber bands that you can find will keep the drum from walking off the roller base. Lobster bands from the grocery store would probably do it. Hope that helps somewhat. I'm trying to remind myself that posting to APUG helps people. Otherwise i'd probably give it up.