The following are the cages I own and use.  They are all from Martin's Cages,  and are all powdercoated, with a drop-in black plastic base.  I have three sets of rats living in the cages, and all have plenty of room and places to play and hide.
Number of visitors
Rat Cages
The following are the cages I own and use.  They are all from Martin's Cages,  and are all powdercoated, with a drop-in black plastic base.  I have three sets of rats living in the cages, and all have plenty of room and places to play and hide.
Here are the three cages, from top to bottom:
R-660
R-670 (with additional balcony and ramp)
R-680
Here are the three cages again, from top to bottom, but with rats, this time:
R-660 (Sam)
R-670 (Max & Tucker)
R-680 (Reilly & Joey)

Since this photo was taken, Reilly and Joey have moved into the R-670, and Max and Tuck have moved to the R-680. 
Max & Tucker
Sam
Reilly
Joey
(Above)  This is a close-up shot of the R-660.  The bump in the hammock is Sam.  The purple tube is from Super Pets, and is a ferret tube. 
This is a close-up shot of the R-670.  Tucker is shown at the top, ext to the hammock.  Max is hiding in the Pepsi One box.  I added an extra ramp and balcony to this cage.  I also added a corner balcony and ladder from PetsMart, along with another ferret tube, and a corner litter pan.  
Sam
Tucker