Eaton's PHB family of supercapacitors integrates two HB family cells with passive voltage management to reduce parts count and simplify designs. They are commonly used in small systems running from 1.0 to 5.0 volts.
PHV Cylindrical supercapacitor pack | 5.4 V | 0.47 F to 5.0 F | Eaton
PHV Supercapacitor
HB Cylindrical supercapacitor | 2.5 V | 3.0 F to 110 F | Eaton
HB Supercapacitor