How to short cut for Delete ?(move to trash)

Im re organising my Libraries As to quicken my work flow.

Instated of having to drag the cursor from the folder to the delete bin each time, It be quicker to have a short cut.

Passing the cursor over the move to Trash it show the short cut , but why keys ,? I do not see this on the key board . or I cannot work it out. Help please .