Jerry;
Not a great picture, but you should be able to get the idea…
The weights are 3.5” wide; they are 1.0” thick; the total height (to the top of the two “nubs” on top) is 3.0”; the height without the “nubs” is 2.5”. They are fairly heavy as they have to balance the weight of the central span, but I can’t dismantle the bridge to get an exact weight - I don’t think that wood blocks would be sufficient without additional weight. Hope this helps.