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 (polegada [Portuguese]) The polegada is a Portuguese "inch" unit, equal to 1/12 pé, 2.777 centimeters, or 1.093 inches.
Length/Distance 
