Single Mouse or Hopper rack.
The single mouse or hopper rack is very effective if you are breeding for certain characteristics. Breed your female to the desired male and then once she is showing move to this rack. This ensures that you know which litter is who's.
For hoppers each tub will hold 5. You can use this as an early way to establish a colony, sort out 5 females and put them in each tub. Once they are adult size move them to a breeder rack and put in a male. This is the most hassle free way I've found of getting a cohesive colony.
You will notice that most pictures are of currently used racks or tubs. We do this to show examples of how you may want to use them.