Product review (1 stars): Manufacturer's note that comes with DLA-D says that it should ...
Manufacturer's note that comes with DLA-D says that it should NOT be used if dishwasher has no *air-gap* device.  Further down, same note says  that DLA-6 or DLA-12 should be used instead.  I also had impossible time detaching tube from GC connector to the point that I decided to cut the hose above the connector and use GC union instead.  DLA-D GC connector is embedded in the device and cannot be replaced.