I would presume the L8 is for Linear 8 in reference to the number of diodes in the corners, but i could be wrong
This is incorrect, the 8 indicates the size. 4 is the short 44" bar, 8 is the 49", 2 is the 55". Info below from the wayback machine copy of Whelen.com
Edge® Ultra™ Freedom™ FL Series Super-LED® Lightbars
Edge® Ultra Freedom features all Linear-LED® technology in a warning package that rivals strobe in impact but provides heavy-duty, long life operation with low current draw. Start with four Linear-LED® (patent pending) modules and add up to eight more Linear-LED® modules (for a total of 12 Linear Super-LED™ modules, or take-down’s, alley’s etc. in just the combination you want. All Ultra lightbars are made for rough treatment and long hours of use.
Features:
- Class 1, SAE and California Title XIII certified.
- Three standard lengths: 44” (44-3/8”), 49 (49-3/4”) and 55” (55-1/8”).
- Rugged extruded aluminum I-Beam construction.
- Available with ScanLock™ flash pattern control that lets you toggle through multiple flash patterns and lock in the pattern you select. Every pair of lights can have its own unique pattern.
- 15' cable, passenger side exit. Driver side cable exit with 25' power cable optional.
- Permanent mount kit MKEZ7 included.
- Custom lengths available.
- Use the Lightbar wizard to configure your lightbar to your specifications.
- 4 corner “Linear_LED®” Super-LED™ modules.
- Add up to 8 “LINEAR8™” Super-LED directional modules.
- ScanLock flash patterns.
- 70% lower amp draw over comparable strobe models.
- Clear outer lenses are standard, optional color lenses available.
Standard Models:
FL4****F - 44.375", 4 Front Facing Blue, Red and/or Amber, For White LEDs Contact Factory.
FL8****F - 49.75", 4 Front Facing Blue, Red and/or Amber, For White LEDs Contact Factory.
FL2****F - 55", 4 Front Facing Blue, Red and/or Amber, For White LEDs Contact Factory.