It is a 9 X 19 mm caliber pistol with a capacity of firing 15 rounds. It runs in semi-auto firing mode.
In the Anime
Envious of Julia's success, Dr. Collins uses a SIG Pro SP2022 to try to kill Julia. As he delays to shoot, David arrives and they face off. Last time the gun was seen lying on the floor spattered with David's and Collins' blood.