Our Tabletop SEM uses a Pfeiffer Hi-Pace80 Turbo pump which is pretty much the standard TMP used in all brands of these smaller SEMs.  There is also a roughing pump.  We offer 2 types. Our EM-30 Plus comes standard with surprisingly quiet Rotary Vane Pump which has an oil reservoir that needs to be drained and filled about every year or two.
The EM-30 Next and EM-30 LE come standard with a more expensive Pfeiffer MVP Diaphragm pump which is oil-free.  This type diaphragm pump is what all other suppliers use (Hitachi, Jeol, Phenom).
If you need an oil-free roughing pump, the diaphragm is the better choice however there are other oil-free pump choices that also produce higher vacuum levels such as scroll pumps.