Coming from a question about [distances between satellites in GEO][1]distances between satellites in GEO, what liquid propulsion systems do a majority of GEO satellites carry to maintain their slot positions? It is easy to find information about Merlin engines, SSME, Rocketdyne F-1, etc., but smaller purpose engines are harder to find.
UPDATE
Thanks for the info about the propellents used. What about the engines? [1]: How closely spaced are satellites at GEO?