Model
2U20ATX300XPR
2U26ATX300XPR
3U25ATX350XPR
3U25ATX550EPS-XR
4U22ATX400
4U22ATX550EPS
Description
19" Rackmount,2U
19" Rackmount,3U
19" Rackmount,4U
Power Supply
ATX 300 Watt SmartPower
ATX12V 350 Watt SL350XR
EPS12V 550 Watt True550EPS XR
ATX12V 400 Watt SmartPower
EPS12V 550Watt
True Power
Case Color
Black
Black
Black
Black
Black
Black
Motherboard
Standard ATX
up to 12" x 9.6"
Extended ATX
up to 12" x 13"
Extended ATX
up to 12"x13"
Extended ATX
up to 12"x13"
Dual Xeon Ready
Extended ATX
up to 12"x13"
Extended ATX
up to 12"x13"
Dual Xeon Ready
Dimensions
3.5"H x 17"W x 19.7"D
3.5"H x 19"W x 25.6"D
5.2"H x 17"W x 25"D
5.2"H x 17"W x 25"D
7"H x 17"Wx 22"D
# of Drive Bays
1 x 5.25" + 1 x 3.5" (External)
3 x 3.5" (Internal)
1 x 5.25" + 1 x 3.5" (External)
5 x 3.5" (Internal)
4 x 5.25" + 2 x 3.5" (External)
4x3.5" ( Internal)
3 x 5.25" + 2 x 3.5" (External)
4x3.5" ( Internal)
3 x 5.25,  3 x 3.5" (External) w/ 120mm fan*
7 x 3.5" (Internal)   
Expansion Slots
2 expansion slots PCI Riser Card included
7 expansion slots
Cage Design
Vibration-absorbing drive cage
Vibration-absorbing drive cage
Vibration-absorbing drive cage
Vibration-absorbing drive cage
Vibration-absorbing drive cage
Vibration-absorbing drive cage
Cooling System
1 x 60mm & 1 x 80mm Ball Bearing fans
1 x 60mm & 3 x 80mm Ball Bearing fans
1 x 80mm & 3 x 92mm
Ball Bearing fans
1 x 120mm intake fan (Default) +2 x 80mm Ball bearing exhaust fans
Front USB ports N/A
Dual front USB socket with shielded cable
Weight
20 / 27 lbs
25 / 32 lbs
33 / 36.3 lbs
33 / 36.3 lbs
38 / 49 lbs
38 / 50 lbs
Side Rails
26" side rails
26" side rails
26" side rails
26" side rails
20" side rails
20" side rails
UPC#
761345-94223-2
761345-94224-9
761345-94325-3
761345-94321-5
761345-94450-2
761345-94451-6
UPC EC
761345-02201-9
761345-02261-3
761345-03205-6
761345-03255-1
761345-04221-5
761345-04225-3
UPC UK
761345-02262-0
761345-02202-6
761345-03206-3
761345-03256-8
761345-04222-8
761345-04226-0
*alternate drive configuration for 4U models:6x5.25 and 3x3.5" external bays with 3 x 3.5" internal drive bays and no 120mm intake fan