The BR Series Coilover is BC's entry level coilover offering ride height adjustability and pre matched spring rates designed for sporty, confident all around handling. They have 30 way combined rebound and dampening adjustability, (upgrade to ER series if you're looking for independently adjustable).
The ER (or External Reservoir) series coilovers feature remote reservoirs with 30 click levels of independently adjustable compression and rebound. Remote reservoirs aid cooling the shock fluid under heavy duty track use or repeated cycling.
The RM (or Reverse Mounted) series coilovers feature an inverted monotube damper. These are found on vehicles that use a McPherson style strut from the factory. They are ride height adjustable only.
HM series coilovers feature independently adjustable compression and rebound with inverted monotube damper
The ZR series are race track ready with 30 clicks of rebound, 15 clicks of low speed compression, and 12 clicks of high speed compression adjustment.