Wylex NHXB16 16A MCB Single Pole B Curve Circuit Breaker. Wylex is a market leader in circuit protection, offering solutions for domestic, commercial, and industrial needs since 1897. The Wylex NH range of 17th Edition compliant consumer units provides easy installation with contemporary styling. The NHXB16 is a 16A, single pole, Type B MCB designed to detect overcurrent's from overload and fault currents. It is suitable for most domestic appliances, tripping between 3 and 5 times full load currents to prevent damage to the installation. The NHXB16 features a positive indication for on or off status. Fuse board, fuse box.