This is the Elinchrom Ranger RX Speed AS Asymmetrical Battery Powered Pack.
The "RX" signifies the ability to be fired by a remote control handset,
or computer. The "AS" indicates the ability of the 1100Ws power pack to
divide power to each of 2 heads asymmetrically. The "Speed" indicates
very short flash duration (when using an "A" model flash head). A
special remote control is available to allow control over settings and
firing from a computer or handset.
Two dedicated heads are
available: FreeLite S and FreeLite A. Following the same head
designations as other flash heads in the Elinchrom family, the A
"Action" heads provide ultra-fast flash duration, whereas the S Heads
produce a "Standard" flash duration (considered extremely fast compared
to other brand's flash heads). Lower the power to 17Ws, and switch to
slow recycle and up to 5100 exposures can be made.
Ranger has flash durations as short as 1/4310 sec. (with 2 "A" heads
attached), ideal for sports, fashion, and theatre photography.
Controls on the pack permit changing the output in 0.1 stop increments in an easy-to-read digital display.