Siteswap Throw 2
Siteswap throw "2" with two hands would be the "2 object fountain". So it would be small throws done in each hand that also land again on the same hand. Because each hand has no other throw to do before catching the "2"-throw again, they can be skipped and just held in the time until two beats later.
The same is true for any asynchronous pattern in which the siteswap number is the same as the numbers on hands.
On asynchronous two-person passing patterns, there are 4 hands, so there are more beats before the same object is thrown again and here a "2" becomes a zip