It's never a good idea to guess with measurements, that's what measuring tools are for. No need to look for a power outlet, since it runs on batteries. Just get at it!
From ManoMano
Bosch 0601069100 LR 2 Professional Laser Receiver BSH601069100
Conrad Electronic
Bosch Professional 0601069100 Multi-line laser receiver Suitable for Bosch GLL 2-50, GLL 2-80, GLL 3-50, GLL 3-80
This product is also available at 2 unverified stores.