the skimmer in that link does not appear to have a beckett injector? (traditional downdraft?)
The beckett name comes from the beckett injector made by beckett (pond supplies). It's really just a cool venturi with 4 air inlet holes and a spear like thing inside to direct the water to maximize the venturi effect.
Search for "beckett 1408"
To see one, look at any Precision marine bullet skimmer. It's the black thing in the clear tube where the water goes in.
Becketts work well, but require a strong pump to operate. Great skimmers, but not as effieicnt as needlewheel skimmers.
