Product review (5 stars): Fantastic little device
Perfect little device for the job.  It fit exactly as promised.  Instructions were clear and easy to follow.  This only works with an existing disposal.  Watts offers a different version if you don't have a disposal.

This device costs more than just a simple drain tap, but it makes service and testing much much easier.  Example.  I wanted to know if the shut off valve was working properly.  Because this device uses a quick connector, it was easy to pull out the waste tube, put a bucket below, and see when system was running.

Also, it makes the system quiet.  Before installing this, I had a simple drain tap,  I could hear the dripping when the RO system was running.  Sometimes I'd forget and run around trying to figure out what was leaking.  Now, I can't hear the water drain at all.  Totally silent.  Hence, the testing method above.

The plastic is a more brittle than I expected, much more like PVC than ABS or rubber hose.  It doesn't give.  So, when I cut off the end, it snapped, I was afraid I'd broken it.

The picture shows two clamps but mine only came with one.  I don't see why two would be necessary.  It is good and water tight even before I used the clamp.