This is for the bag ONLY.  NOT THE PLASTIC UNIT, Just a better bag to put on it.  The drawstrings are replaced with an O-RING sewn into the material for EZ on/off handling.  Just snap on the unit, and pull it off with the handy tab. 

There are 2 size of bags 20" Depth and 36".

This is for the 36" BAG which comes with rubber O-Ring on top and a foam insert to keep the bag upright under low water pressure.