Product review (3 stars): I followed the installation manual drill a hole on draining pipe although I don't like this way (too tricky and may break code)
The size of QC hose size in 3/8" rather than 1/4". If you intend to use the QC hose connect to a RO system drain pipe, it may not work at lease for Home Master products because the drain pile is 1/4". It seems that the product use the inner diameter rather than outer diameter. For 3/8" pipe, its inner diameter is about 1/4".
Finally, I have to cut it and use the main hose to connect my dishwasher drain pile after removing the air gap (I need to use the hole for RO faucet). For RO drain pipe, I followed the installation manual drill a hole on draining pipe although I don't like this way (too tricky and may break code).