The SREDKey 2 was designed from the start as a Form-Fit-Function replacement for the SREDKey with the exception to the features highlighted in blue below:
SREDKey 2
PCI v5.x
15 key Encrypting key pad, Same reliability with improved tactile feedback
Display: 2.9” LCD Display
Dimensions: v160mm x 96mm x 37mm
SREDKey
PCI: v3.x
15 key Encrypting Key Pad; 4,000,000 key presses for each Key
Display: 2X20-character LCD backlit display
Dimensions: v160mm x 96.7 mm x 37 mm