I believe it was a leisurefurl boom. We had a full batten large roach main, and this was the only way to preserve that cut on the sail.

It actually worked quite well... provided the boom was at the right angle and as others pointed out, you took the load off the sail.

I found it could be reefed quite flat and tight in heavy winds once the sail was taken up, and then the mainsheet and vang were tightened.

The owner had one powered winch, this was situated to be the winch for the main halyard.

Certainly one solid advantage of the in boom furler over in mast is that you can still "drop" the sail, even if the furler fails...

The one thing I didn't like was the overall size of the boom... the thing was nearly 14 inches across.

The other thing to watch is where the luff rope is fed into the guide that feeds the mast slot. It always looked like a failure point, and I suspect as the luff rope wore a bit, it might be trouble.

I sailed on this boat on and off for 2 years with this system and overall felt it worked well. This boat was also in charter and thus got quite bit of "abuse" from the public.