The datasheets indicate that the peak forward voltage is 1.1.The reverse voltage range of this device is 420 at its peak.System forward voltage should be kept above 1.1(V) volts.A maximum reverse voltage of 600 V is specified in the applicable device specifications.
RBU605M Features
the forward peak voltage is 1.1 the peak RMS reverse voltage range of 420
RBU605M Applications
There are a lot of Rectron RBU605M applications of RF diodes.