The 1N5351B is a Zener Diode with cathode band polarity.
The 1N5333B series Surmetic™ Voltage Regulator Zener Diode with tight limits and better operating characteristics that reflect the superior capabilities of silicon-oxide passivated junctions. All this in an axial lead, transfer-moulded plastic package that offers protection in all common environmental conditions. All external surfaces are corrosion-resistant and leads are readily solderable.