For use with all Wylex 'NH' consumer units, including the new 17th Edition consumer units, Wylex NHXB MCBs (Mini Circuit Breakers) protect electrical installations by detecting both overloads and fault currents and interrupting the electrical supply.
Wylex NHXB MCBs or 'breakers' are subject to slight design changes, and those now supplied may differ aesthetically from the ones appearing in your board. All are interchangable however.
The NHXB range of MCBs are 'B' Type breakers, this means it will trip between 3 and 5 time full load current which is suitable for most domestic installations. If you are at all unsure you should check with a fully qualified electrician