that attaches to your ankle and trails behind you) we went straight to the scuba 7. They are great prob only issue is the electrical chords can get tangled aroud your equipment at times and takes a bit of getting used to.  You will see 2 long rectangular pieces of neoprene/foam attached to the bracket that attaches to the tank strap. The flat plate electrode sits on them and they fall off easily cos they are only glued on so we wrapped zip ties around them to hold them in place jusr letting you know because they are easy to lose.

I've got the freedom 7 and it's a bit of a pain when diving on scuba. the leash trails over a metre behind and can get caught in crevices when diving for crays. It is however better suited when free diving. If you are only diving on scuba then definitely get the scuba7. as berroclock said, make a few make-shift adjustments and it will work much better for you.

Although a bit fiddly to get on, the shorter lead off the ankle is pretty easy to dive with.

I just shove the plate under the tank mesh and seems to hold it in place fine.

cheers

brett

http://www.sardi.sa.gov.au/__data/assets/pdf_file/0005/173876/Risk_Assessment_of_the_Shark_Shield_Report_-_FINAL_19_06_2012.pdf