(It will be difficult to answer this question without 'advertising' for a retailer, but I've searched for these several times in the past few years, to no avail.)
In Math From Three To Seven (The story of a Mathematical Circle for Preschoolers), the author makes frequent reference to a set of plastic shapes, each of which has four attributes:
- Colour (red, green, blue, yellow)
- Shape (square, circle, triangle)
- Size (big, small)
- Holiness (it, uh, has a hole in it. Or it doesn't)
The set is complete - all $(4)(3)(2)(2) = 48$ blocks.
The footnote in the text refers to these as "Dienes Blocks", which today, are "universally known and easy to obtain". The problem, though, is that searching for 'Dienes Blocks' returns different products from the same manufacturer / brand / personal legacy of Zoltan Dienes - namely Base-10 blocks.
From ZoltanDienes.com,
Dienes’ name is synonymous with the Multi-base blocks (also known as Dienes blocks) which he invented for the teaching of place value.
That's great and all, but how do I find these other blocks?