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
Unit Definition (pe [Portuguese]) The pe is a traditional Portuguese foot, equal to 12 polegadas or about 33.324 centimeters (13.12 inches).
Length/Distance 
