Not sure if these are available nationwide - I purchased today here in Spokane Valley, WA, in the pet food section. They are rated to hold up to 54 lbs of dry pet food, measure 14.8" x 18" x 23.8", 69 qt / 17.25 gal, and come with castors (optional to put them on) and a heavy duty plastic scoop.
As you can see, it easily holds a 55 lb full bag of malt, and is of decent but not super heavy duty clear plastic -- appears to be strong enough to fill with malt, although I plan to stick pretty close to the rated weight. The seal grommet is not rubber, rather appears to be small cell weather stripping, but matches well and covers the rim. It is very lightweight and I think the castors work well enough when fully loaded, especially on a smooth floor. Very competitively priced here. I paid $15.79 + sales tax. And made in USA. I'm going to get one or two more tomorrow - beats lifting Rubbermaid tubs, and seal is considerably better, although not stackable like Rubbermaid tubs.