Wilton power arm, they may not manufacture them anymore, you can still find them used.
New try this place
https://www.wdscomponents.com/en-us/powrlock-hydraclamps-long-arm
Look at this company I’ve heard good things about them.
https://www.harveywoodworking.com/products/alhpa-hw615pro-3hp-15-stain-less-bandsaw?variant=44693094793434
Josh
Here’s my keel design I use. I can wrap then decoy line around it, and the belly cutout I seem to get more movement. If I need weight or less I can do that to.