I bought the smallest one they have, not the rod holder, just the seasucker, I think it's 4" or maybe 6" ?
I got it to mount a fire extinguisher out in the cockpit. It held.....for about a week, then it falls off. What I did was moved it down so the weight of the extinguisher was on the cockpit floor. Then it's fine tucked under the gunnel. Would I buy another? Probably not, they are expensive and do not appear to work as advertised.
I think the instructions say NOT to wet it before you mount it. Well, I found out the oposite is true. It lasts longer if you wet the suction cup first before sticking it to whatever. :huh: