There are three SPHINX SDP Compact models released for the US market:
- SDP Compact
- SDP Compact Alpha
- SDP Compact Duty
All three models feature a steel slide with hard anodized aluminum frame.
Grip Size
SDP Compact and SDP Compact Alpha have the same size compact grip.
SDP Compact Duty has a larger, "full size" grip.
Grip Material
SDP Compact grip is hard anodized aluminum.
SDP Compact Alpha grip is made of advanced polymer composites.
SDP Compact Duty grip is hard anodized aluminum.
Magazine Compatibility
| SDP Compact | SDP Compact Alpha | SDP Compact Duty | |
| 15rd Magazine | Yes | Yes | No |
| 17rd Magazine | Yes | Yes | Yes |
The longer 17rd magazine with the SDP Compact and SDP Compact Alpha will extend beyond the bottom of the grip.