French Dimmer switch

[captainkiwi]

I recently bought a \\\"Legrand\\\" dimmer switch which has four terminals marked L, L, S, and wavy line with an arrow through it. Using a multimeter on it showed me that L and L were permanently connected but there was maximum resistance between all other connections i.e. L to S, L to X, and X to S, regardless of switch position. It\\\'s a plastic switch (no earth) but no instructions. I thought it was broken but the replacement is exactly the same. Is it just that my multimeter is operating d.c. on the resistance setting and the switch is for a.c. use? Any help with the correct wiring for it will be gratefully received.