Comments about Roberts Roberts Saltwater Series Rod Holder:
There needs to be a Left/Right model so they can be mounted on either side of the boat with equal clearance.
Also, if you use a reel seat clamp, they're simply not wide enough.
A Penn 500 won't fit with clamps.
The good news is, you can simply close the locking mechanism and they're as good as any "tube" style holder. Since they swivel, they're better!