This plastic piece is removable and washable. If it weren't, I wouldn't still have it. I am known as the one with little patience and it has pleased me. To change the bag, you just lift up on a white tab, pull the plastic piece that allows the diapers to fall in, take the bag out and replace. The plastic piece the allows the diapers to go in, is much like a claw.
Pressure causes it to open.
You then replace this piece over the bag and close the top. After 3 months of that dreaded trash can, I bought this wonderful pail. It has held up through many diapers. All the pieces are still in tact. It is small enough to put anywhere.