Actually had to look it up the first time I heard the term HenleysTo avoid regional differences in what things are called. I should have called them hollow wall anchors. But if I ask for a box of dry wall anchors at a certain size and that's what I get. If I ask for umbrella or brolly fixings I'd get a confused stare.
Same as 100A Service blocks, we call them Isco's, you call them Henleys