Boom Crutch?

Can anyone send me a pic of their boom crutch? I have a metal fairlead thru deck fitting at the aft end of the cockpit with a corresponding socket pad on the floor of the hull which I assume is for the boom crutch... but I've never seen one. I would be very interested in knowing the length of the crutch from the bottom of the boom saddle to the pole end.

Thanks in advance,

Bob Klein