Model 51 - Reel seat or Deckhand style.
Penn reels
Set the opening the mounting post to the widest and measure.
These are 1-1/4 inch center to center on the mounting post.
Old Penn wingnut clamps do not work with trigger clamps
Please loosen the 2 nuts so that bolts are loose and wiggly. Install the clamp over the studs, secure the barrel nuts to that they line up to the grooves in the clamp Secure the barrel nuts to snug fit. Tighten the loose nuts on the frame. Then snug up the barrel nuts. Check for alignment .
jigmaster 501
squidder 146
Fathom and Squall 12, 15, Fathom 15XNLD2, single and 2 speed.
Penn GS 525
Note: please use factory Penn hardware.