The W51-A121B1-5 is a 1-pole rocker actuated switchable Thermal Circuit Breaker with 0.250-inch (6.35mm) quick-connect straight terminals. The 1423673-1 calibration breaker will continuously carry 100% of rated load. It may trip between 101 and 135%, but must trip at 135% within one hour at +25°C.

Specification
- Angular button design
- Black base
- Red (translucent) rocker
- Illuminated light
- Reset/off printed marking
- Compact and trip-free design
- Provides circuit protection and power switching in a single unit
- Snaps into the same cutout as many common power switches
- Ten times rated current resettable overload capacity
- Typically 6000 operations at 100% of rating switch endurance cycling
- 1500VAC (60s) Dielectric strength
- 100MΩ Insulation resistance
- Series: W51
- Type: Thermal
- Current Rating: 5 A
- Voltage Rating AC: 125 VAC
- Voltage Rating DC: 50 VDC
- Number of Poles: 1 Pole
- Actuator Type: Rocker
- Minimum Operating Temperature: 0 C
- Maximum Operating Temperature: + 50 C
- Illuminated: Red
- Brand: TE Connectivity / P&B
- Height: 27.9 mm
- Length: 21.8 mm
- Mounting Style: Snap-In
- Product Type: Angular Button