millimetres
The thickness is of the order of a millimetre so a smaller unit - a micrometre, perhaps - is suitable.
Millimeters, or centimeters.
inch
mm
You would use millimeters (mm) to measure the thickness of a house key, as it is a small unit appropriate for measuring such dimensions.
You would typically use millimeters (mm) to measure the thickness of a coin. This unit is commonly used for measuring small distances or thicknesses.
The thickness of a coin is typically measured in millimeters (mm). This unit provides a precise measurement suitable for the small dimensions of coins. In some contexts, thickness might also be expressed in inches, but millimeters are more commonly used in numismatics.
The most appropriate unit for measuring the thickness of a feather is micrometers (microns). This is because feathers are very thin, typically ranging from about 100 to 200 micrometers in thickness. Using micrometers allows for a precise measurement that accurately reflects the small scale of feather dimensions. Other units like millimeters might be too large for such fine measurements.
You best bet would probably be to use kilograms.
The Unit - 2006 The Broom Cupboard 2-12 is rated/received certificates of: USA:TV-PG
It's asking for how thick it is not the length of it. So the obvious answer is not centimeters or meters. It would be millimeter.
You need an Engineer's Micrometer which will be accurate to either 1 hundredth of a MILLIMETRE, Or to 1 thousandth of an INCH.