The Denon RMR3313 Rack Mount kit is designed for the following models: X4500, X3500, X4400, X3400, etc.
Denon RMR3313 Rack Mount Kit 
The Denon RMR3313 Rack Mount kit is designed for the following Denon models:       
DEN-AVR-X4500
DEN-AVR-X3700
DEN-AVR-X3500
DEN-AVR-X4400
DEN-AVR-X3400
DEN-AVR-X3300
DEN-AVR-X3100
DEN-AVR-X4300
DEN-AVR-X6300
DEN-AVR-X6400
DEN-AVR-X6500
DEN-AVR-X4100W
DEN-AVR-X5200W
DEN-AVR-2313CI
DEN-AVR-3313CI