LEGO pieces have standard sizes so LEGO structures are usually multiples of those dimensions. The Fundamental LEGO Unit (FLU) refers to the height of a simple brick, and can be expressed in standard units, such as the millimeter: the vertical FLU is 9. 6 mm. since a full vertical unit is 9. 6 mm high.
Can Lego connect to Duplo?
DUPLO ® and LEGO ® bricks are compatible, so you can use them together. LEGO ® plates also won’t fit on DUPLO ® parts, and neither will LEGO ® parts with an odd number of studs along one side. For example, a 2×2 or 2×4 brick will fit, but a 1×2 or 2×3 brick won’t.