Is there a stencil or easy way to label objects (callouts)?

I could swear that in older versions of OmniGraffle, there were stencils that were basically a text label (somewhat stylized) with a line attached that you could use to label something in a diagram you were making - what I would name a “callout”. I don’t find anything like that anymore - does anyone know of a stencil library like that, or an easy way to do that?

I am not talking about making a connector line between things and then labeling that line. I am talking about something like “Thermometer -->” pointing at or connected to the thermometer in my diagram.