Whatever they call them, seems like there's a hundred names for them now.

What are the good brands similar in size to planos 3750?

Is there a chart for series numbers and sizes?

Flambeau 5000 series are similar to Plano 3700: http://www.flambeauoutdoors.com/fishing/default.asp?p=Details&c=FRESH+AND+SALT+WATER&s=TUFF+TAINER&i=5007

I just checked them out, they look a lot more durable then the planos, I have to figure out how I need for now

I don't like the Flambeau's. They came with my soft side box, and I threw them all in the storage closet and replaced them with Plano's. They flexed too much, the corners of one of them opened up enough to start letting my weights fall out. The latches are easily unsnapped, even just coming undone when I grip the box near the latches. This caused a very unfavorable problem one day with about 30 crankbaits flying all over a carpeted floor, which prompted the throw-away.

I've had problems with Flambeau boxes developing cracks at the injection point. I've only tried Plano, BPS, and Flambeau so far, but I've been pleased with all of my Plano purchases.

Ditto on the Flambeau products. I don't think that they are made as well as the Plano ones.

Just stay with Plano IMO.

I have both, no difference, though the Pro Latches are nice. I usually use a solder gun to perforate mine for better drainage:

I only use Plano FTO