My brother and I bought these so far its working okay.
there is same unit with one receiver at 10p more.
hope not a repost did search
2 parent units included.
Portable parent units with clip.
Range up to 120m.
Sound sensitive light display.
Low battery indicator.
Each parent unit requires 3 x AAA batteries for portable use (not included).
Mains adaptors are provided for both baby and parent unit.