From The Stargate Omnipedia
A powerful vessel under Replicator
control. It is most likely that the Replicators seized control of the vessel from the species that created it. But the advanced ship has proven extremely effective in defeating enemy vessels, allowing the Replicators to spread to a ship disabled in battle and spread to other parts of the galaxy.
The ship is armed with advanced shields and weapons which are capable of disabling even the largest Goa'uld craft, including Apophis's mothership. Upon encountering a new type of craft, the Replicator patrol ship launches a blinding, yet harmless scanning beam. Vessels that are not deemed a threat -- or of sufficient technology to infest -- are ignored.
USED BY - Replicators
FIRST APPEARED - Enemies
Enemies - Moments before Apophis decides to destroy SG-1 and Jacob Carter, a Replicator ship emerges and engages in battle with the System Lord, disabling and infesting his mothership. The patrol ship mysteriously disappears.
Unnatural Selection - A Replicator-controlled ship scans the Prometheus on approach to Halla, and does not find her to be a threat.