For an electronic component in the 230 range of switches already seems adventurous to: no VDE certification (CE only), company is located in UK, IP44 protection (ie for outdoor use) hardly believable (no rubber gasket), poor relief etc .. The electrical connection should definitely not make a layman, but at least one semi-professional. For the connection you need the two lamp wires + phase + Zero! Connect directly to the outside lantern so do not go. But that part does not bad! Installation must be "upside down" by the way.
Addendum: before using the second twilight switch I once gemessen- own consumption of the switch and there's the rub: the part needs without load 5 W, while the power with load at least about 2 watts. In an LED lamp with 3 Watt to use so definitely not worth at 8W or 11W energy-saving lamps already. But the savings are minimal.Dafür a star deduction.