The red piano dolly is waterproof with 4"swivelling and locking, SS ball bearing vinyl wheels, rated for 250 pounds.
$20
The black one, also waterproof, is welded 3/36 inch steel plate with 10 " solid wheels, 1/4" steel axel, rated for 400 pounds
Removeable wood braces for multiple applications. It was used to move logs, equipment. tool boxes, welder etc.
$20
The 2 ton rated, redwood dolly on the bottom of the pile has 6" SS ball bearing wheels and is available in my other CL ad for $100 - used a few times to move cut stone.