The Canon Off Camera Shoe Cord 2 maintains all on-camera flash functions
(including E-TTL) for one Canon Speedlite used off-camera at distances
up to 2 ft. (60 cm). It is compatible with all Canon EOS cameras except
the 630 and RT(which require a combination of TTL Hot Shoe Adapter 3,
OA-2 Off Camera Shoe Adapter & Connecting Cord 60). It is also fully
functional with the combination of the T90 camera and 300TL flash(from
Canon's older FD manual focus system).
If you will be attaching and detaching the Off Camera Shoe Cord 2 from a
flash bracket upon a regular basis, it is advised to avoid wear upon the
bottom by purchasing the optional Bogen 3298 adapter to act as a
'sacrificial foot' for the slightly delicate bottom of the Off Camera
Shoe Cord 2 itself.