Works very much the same as trigger except that when you use 'a' for creation arguments, lists that consist of only 1 atom will output as the atom itself and not as a list. This also includes pointers. You'll notice that with trigger, a pointer will output as a list, which makes it difficult to type-check.
The [unpak] object had a similar problem where it would output lists instead of raw atom values, and that has also been changed with unpak's latest update.
EDIT: I've made it so that floats default to anything outlets and no creation args defaults to 2 anything outlets.