Door openers (4)
I believe the answer is:
keys
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">door openers</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for keys that I've seen before include "Musical scales" , "Openers - low-lying islands" , "Low islands, sycamore fruits" , "House of ----, IoM legislature" , "Landing places" .)