Our smooth sanded spruce blocks are finely sanded small on all sides and edges and may have a few small knots on the sides or back.  All of our blocks are individually cut and sanded by hand and are therefore there will be minor differences in dimensions of each piece with all sizes being approximate as follows:
Mini square 2.5 x 2.5 x 1.5"
Small square - 3.5 x 3.5 x 1.5"
Mid Rectangle - 4 x 4 x 1.5"
Medium Rectangle - 5.25 x 5.25 x 1.5"
Large Rectangle - 7 x 7 x 1.5"
XL Rectangle - 9 x 9 x 1.5"
XXL Rectangle - 11 x 11 x 1.5"