Rinnai R85 (REU-V2532W):

 An exterior (outdoor) continuous-flow gas hot water system delivering up to 8.5 GPM, popular in mid-2000s residential installs.

• Rinnai Model 2532 (Continuums): An indoor/outdoor unit widely deployed with PVC venting that ran on natural gas or propane.   

• Rinnai Model 2533: