To be very general the edge went through a few phases.
1984ish
1-"V" shaped corners with 7x3 linear "mini max" inboards (I'm still looking for one of theses FYI) Single or double flash
1990ish
2- "J" shaped corners with 4x3 in boards - Usually Double flash
1994ish
3- "Turbo tubes" a combo unit housing 1 corner strobe (linear) and 2 twist-lock 4x3-ish sized inboards that could be halogen on strobe. Usually comet flash
1996ish
4- "Turbo tubes" with a linear bulb on the inside and corner and ad a 4x3 sized head in the middle
1997ish
5- "Linear ends" with slide in other options of both linear, halogen and other types
6- "Duplex" "E" series- the corner strobes might be angled or might be front facing with side facing half height strobes with alleys on top (the front was the same way, full or half height halogens and strobes).
1998ish
7- "Ultra" series, wider, the same width as the B-Link bars. All linear generally.
1999/2000ish
8-Edge Patriot- Shorter slimmer edge, quickly retrofitted with 5mm led 500 series inboard lights and the 500 series
TIR lights and eventually the 500s we know today. These bars were the "gateway" to LED bars and were not strobe bars for long.
2002/2003ish
8a- "9M" essentially strobe Freedoms. The corners were angled full size linear, everything else was a 400 series strobe or halogen. Theses were very easy to replace with 400 LEDs and Freedom corners.
2004-2012?
Many of the previous bars lingered on, the (9M specifically and the Ultra). LEDs were taking hold and the era of strobe bars was ending.
A few more later catalogs as the lines between the Ultra and 9M blur some duplex options remain in 400 series form. The Patriot is officially part of the edge line.
2002-2007
The edge (strobe version) is down to one page in the general 2007 catalog and in the fire specific catalog the Freedom is considered a type of Edge. The same year the Patriot drops the term edge from the bar.
One of the ways Whelen slid into the LED market despite other smaller companies being technically first is the ability to retrofit the edge with LDEs. The Freedom is an edge with 400 series LEDs and the Patriot Simply started switched to 500 series LEDs.
B-Link, The original wide frame all linear strobe bar from 1996