Compatible cups
Whether grabbing a mug or tumbler from your kitchen or shopping for a new one, you can be confident the following brands fit the Ruumi lid.
Yeti
Tumblers: 10, 16, 20 oz
Mugs: 10, 24 oz
Fit: good
            
          SIC
Tumblers: 12, 20 oz
Fit: good
            
          Ozark Trail
Tumbler: 20 oz
Fit: good
            
          Swig
Tumbler: 22 oz
Mugs: 12, 18 oz
Fit: good
            
          Ello
Tumbler: 24 oz
Fit: good
            
          Asobu
Tumbler: 16 oz
Mug: 12 oz
Fit: good
            
          Tervis
Tumbler: 20 oz
Fit: good
            
          CeramiSteel
Tumblers: 16, 22 oz
Mug: 12 oz
Fit: good
            
          Taste the Earth
Tumbler: 16, 10 oz
Fit: good
            
          Sodilly
Tumbler: 16 oz
Fit: good
            
          Umite Chef
Tumbler: 20 oz
Mug: 12 oz
Fit: good
            
          Hydro Flask
Tumbler: 16, 22 oz
Mug: 12 oz
Fit: Extra snug
            
          Reduce
Mugs: 14, 18, 24 oz
Fit: Extra snug
            
          * Most cups have an excellent fit. A few may feel slightly loose, but no leaks have been observed. 
** Lids can be used but they are harder to install and remove.
Other brands
GATR
Tumbler : 20 oz
Meway
Tumblers : 16, 20 oz
Mug: 12 oz
Domicare
Tumbler : 20 oz
Hasle Outfitters
Tumbler : 20 oz
FGA
Tumbler : 20 oz
Jay Style
Tumbler : 20 oz