The KBL406 is a thru-hole, single-phase silicon bridge rectifier commonly used to convert AC to pulsating DC, then smoothed with external filtering capacitors for stable output.

Features :

• High surge handling: Up to 200 A surge current capability ideal for cold‑start or AC to DC transitions.
• Low leakage: Minimizes standby power loss and heat buildup.
• Reliable and Compact: UL‑rated, flame-retardant plastic package for safety and board-level durability

Specifications :

• Repetitive Peak Reverse Voltage (VRRM): 600V
• RMS Voltage (VRMS): 420 V
• Maximum DC Blocking Voltage (VDC): 600 V
• Output Current (IF(AV)):4.0 A
• Forward Voltage Drop (Vf):~1.0–1.1 V @ 4 A
  Reverse Leakage Current (IR):~10 µA @ 25 °C
• Operating & Storage Temperature Range: –50 °C to +150 °C
• Package Type: KBL-series flat, molded plastic case (through-hole) with four solderable leads
• Material Certification: UL 94 V‑0 flame retardant plastic; UL‑recognized component (UL file E54214) 
• Mounting: Designed for PCB mounting; includes built‑in PCB stand‑offs
• Typical Dimensions: ~20 mm × ~6 mm × ~55 mm

Supplier link: http://www.farnell.com/datasheets/62567.pdf