From the FASA Star Trek ROMULAN SHIP RECOGNITION MANUAL, circa 1985
H-4 (Praetor) Class II Warp Shuttle
Known Sphere of Operation:  Empire-wide use
Data Reliability: A 
Major Data Source: Vessel in Starfleet posession; Triangle sector intelligence.
    The more popular of the two major warpshuttles, the H-4 lives up to its name (Praetor translates as 'leader'). Its spacious quarters are the most luxurious of all Romulan
shuttles, and, therefore, makes for the most desired and comfortable travel. With a crew of two and passenger facilities for eight, it is considered to be large for the mission
requirements. It is found either ground based or attached to an outpost or orbital station, probably due to the vessel's size, but some are known to be carried aboard Class
V or larger vessels. The H-4 carries out courier and VIP transport duties for both the Navy and government agencies throughout the Empire; as it is not armed, it is not
usually seen in sensitive areas.
    Production of the Type 1 appears to have slowed drastically  after the introduction of the Type 2. Sources report that as more and more Type 2s became available,
the Type 1s were taken out of production, and those existing models were refit and modified as Type 2s. The Type 2s use a newer, lighter version of the same engine,
which requires less space and allows more room in the crew compartments.
    Of the approximately 2,500 H-4 warp shuttles built, about 2,000 are still in service. About 30% of the remaining vessels have been lost or destroyed; another 40% are
in the reserve fleets. By best count, at least 28 Type 1s and 121 Type 2s are operating in the civil sector. Current production capabilities are estimated to add an
additional 50 Type 2s per year to the number in service.