I can’t recall where but someone recently asked me if the keypads on the Gigaset SIP/DECT handsets are backlit. At that very moment I didn’t know, but I have since confirmed that all three (A58H, S67H and SL78) are in fact backlit. Here’s a composite image of all three handsets to illustrate that fact.
The backlight is most obvious on the S67H model, even in the day time. However, all three are lit well enough to make them usable in a dim or darkened room.