There are multiple types of FTL drives with different costs, capabilities and sizes. They can generally be differentiated by their compactness, efficiency, durability, cost, and minimum charge time. As an example, the Rook Dynamics RD-1000 FTL drive used by the Raptor IIIs of the Colonial Navy is very compact, with high durability, rapid charge time (fastest ever in a production FTL drive), high fuel consumption, and extreme cost (3 million Cubits a unit, a large fraction of the Raptor III's 10 million Cubit cost).
FTL drives usually mass between one 8th and one 12th of the vessel's mass. In general, lower quality drives take up more mass than more advanced versions. The standard for civilian ships is around one 8th to one 10th, while military vessles try to get closer to one 12th mass.
One of the other inportant factors is the compactness of the drive. The more compact a drive is, the less of the crafts volume it takes up, but the more difficult to produce and harder to maintain. It also has negative effects on fuel efficiency.
FTL jumps cause stress on the FTL Drive. Many jumps in a short amount of time can cause major damage to a drive, leading to it baing inoperable. Civilian ship usualy have less durable drives as they don't need to rapidly jump.
It take a while to charge a FTL Drive as charging a drive too fast can cause damage to the drive. Most civilian FTL Drives are designed with a charge time of between 40 and 60 minutes, while miliary vessels have lower charge time of between 15 and 5 minutes. Charging a drive far faster than a drives Charge Time is called Quick Charging.
[More in depth explanation planned, but was scrapped]