The 544 is the Medium-length version of the GoPro adapter for SL A/AF.
For a pure head over-mounting (vertical) we recommend the version “M”. If the holder is aligned frontally (horizontal) we recommend the version “S”.
Please note that while this is supplied with two o-rings: in most cases, only one is necessary to be effective. Therefore, always first try to mount the lamp-head with only one of the o-rings!
(i.e. put the screw with the mounted o-ring through the arm, and screw into lamphead; if needed, use other o-ring between arm and lamphead)
Arm length (back stop to middle screw):
Version L: approx. 42mm
Model M: approx. 35mm
Version S: approx. 22mm