Manufacturer: MANSFIELD
Lid P/N: 51
Lid Size: 20" x 7.5"
Tank P/N: #35
Tank Size: 18.875" x 7"
Also sometimes marked as MPP-51, Mansfield 35, KPP 51, and often mistaken as 61-71 or 61-72-2.
As you can see in the accompanying photos, it is very hard to tell the difference between white, biscuit, and almond. In the photo showing white and biscuit, biscuit looks very dark, but in the photo showing biscuit and almond, biscuit looks very light. White is the lightest, almond is the darkest of the three, and biscuit is about halfway between the two. Biscuit is much more common than almond. White is the most common.