Convert from stick to zeptometer

Unit Definition (stick)
A stick, when used as a unit, is usually two inches, i.e. 5.08 cm (for the international inch). It was once used in the English tailoring business, but has since fallen out of use completely.

Unit Definition (zeptometer)
The zeptometre (or zeptometer), symbol: zm, is an SI unit of metric length measurement. 1 zeptometre is 1e-21 metres, which is a very small distance