J bought this motion detector for my son born on 19 March. I took this model with charger and walkie for I had read that the only detector (without charger) required great battery consumption! for 30 euros more you'll be widely winner! My nights have returned peaceful! more anxiety! It is amazing precision. a beep sounds with each breath. The downside of this machine c is the "poc" strong enough that it makes every baby breathing. it's pretty painful night. The trick I made c is turn the walkie, which takes over the plant, and place it in another room. So I no longer hear the "pop" but am alerted by a rather large bell in case of problems! I recommend this product for all parents flipes like me! (I have a cot with a super thick mattress so it is adaptable also on what kind of bed)