The Omron MIT Elite plus is a home use digital automatic blood pressure monitor. It’s highly portable, has a slim design and a large display and can be operated with only one button. It’s extremely easy in use.
The Philips Avent SCD498 Baby Monitor can reach as far as 300 meter in open field or 50 meters in houses. It has signals to notify you when the connection is lost. I never had problems using it. Find its manual / user instruction in PDF below.