Hi there, Bill.

:Why the 500 over the 400

While the pump bodies are the very same size, the larger, 1.5" O.D., inlet and outlet of the 500 gives it a greater pumping capacity than the 400 can do with its 1" O.D. fittings. Their website says the 500 will do 15 G.P.M., and the 400 will give you 10 G.P.M. The drawback to the 500 is that the 1.5" hole has over twice the cross-section area as the 1", and it looks HUGE on the deck of a kayak. I've heard of that being disguised as the base of a compass, but I mount my compasses somewhat more forward than that so I can read the numbers without my glasses. Instead, I adapt the 1.5" outlet down to fit the 1" diameter deck-mounted nipple. I lose some flow, but it's still going to have a greater capacity than the 400, and around here the 500's are sometimes cheaper than a 400, depending on where you shop.

:What kind of foot braces are those?

That's an ordinary pair of plastic Keepers, with 'faceplates' of 1/8" sheet PVC screwed onto them. By making a fold on one side, I got them to be stiff enough. A tad bit more comfortable than the smallish originals.

o you have a picture of the bungie system?

Sorry no; but it's as simple as it sounds. I'll send you a photo after I get back from vacation.

Pete