The Ermes Leonardo speargun reels are the only reel on the market that automatically align the spool while retreiving line. This makes re-spooling the line much faster, easier, and more organized. 
Titanium frame has minimal affect on bouyancy. 
True drag system allows multiple drag settings
Mounts directly to trigger guard
 
L57 capacity: 50m of 1.5mm / 30m of 1.9mm
L77 capacity: 100m of 1.5mm / 60m of 1.9mm
 
Note that the Leonardo reels are setup so the crank is always on the right side of the reel (with the speargun rightside up) and it is wound in a counter-clockwise direction. 
 
* All reel line is the best on the market - Aussie Line Pro