Complete Range of ERA Nightlatches. These locks are Ideal for front door security. ERA Nightlatches can be deadlocked from the inside for added security. At Buy Locks we supply the 1830/1930 ERA British Standard 3621:2007 Nightlatches. 183/193 ERA Double Locking Nightlatches, 1430/1630 ERA Standard Nightlatch, and 133 ERA Traditional Nightlatches. All nightlatches are available in 60mm or 40mm, brass, satin, chrome, nickel, green and grey.