Niobium solid-electrolyte capacitors differ from tantalum solid-electrolyte capacitors in anode material: instead of tantalum powder niobium powder is used. In the same working temperature range (-40°С … +60°С), leakage current values are comparable for both tantalum and niobium solid-electrolyte capacitors; niobium capacitors can successfully substitute tantalum solid-electrolyte capacitors.
K53-4
Is a hermetically sealed capacitor of high reliability.