Pentacubes are puzzle pieces, each one made up of five cubes glued together
The name pentomino (like "domino" only 5 squares) is used for the flat shapes
There are 12 of them and they can be fitted together in many ways (the square in the middle is just a filler)
They are made from square section timber about 68mm x 68mm
The pieces are cut on the bandsaw into lengths which are 1, 2, 3, 4 or 5 units long
This is the P-pentomino (or P-pentacube) a 3-unit and a 2-unit joined together