Hello today I am going to share my own experience with Nova NHC-3921.Nova is a most populer brand for trimmers.I baught a nove nhc-3921 trimmer about three months ago.this is not a perfect trimmer .i am facing many problems with it and the cost of it is more than other trimmers in market.the battery of this trimmer is very poor.i charged up full but this work only for 20 minutes so I hate this one.Sometimes when I use this trimmer I dont get clean save. I think that this is a useless trimmer and I never reccomend anyone to buy this.if u are going to buy a trimmer dont buy this one.thank you.