Even with 2 sets of new batteries & following the instructions exactly, this monitor never worked! Very simplistic to use, but only had a horrible noise generate from everything I placed the sensor on....couldn’t hear my own heartbeat, even though you’re supposed to be able to. Bought for my 1st child’s baby shower so my Mother & Mother-in-law could hear & record my LO’s heartbeat, but went empty handed instead, since there was no time to purchase a different brand. You’re supposed to be able to hear your heartbeat & baby’s, but my coffee table & palm had the same buzzing “heartbeat” my baby had! What a huge disappointment! Purchased a different brand after shower & it worked amazingly. This is too important of an experience to have such a huge flop. You don’t have forever to record such a precious moment in time & you can’t go back & do differently later either. I would definitely buy another brand! Such a disappointment!!