Loud, authentic vintage sounding signal flasher

[davepl]

What do I look for, besides buying one from an auto parts store adjacent to a senior center perhaps?

When I was a kid, the originals made a distinct "TEE-KU" sound. Yes, that's my best effort at typing the sound. And I just had my hearing tested before the obvious answer is offered :-) About all I hear now is the clicking of the relay, which isn't much on a modern relay.

But even though I have non-electronic, they're still not loud. I was thinking of taking a 9V battery with me and trying them out, but maybe there's a better way, like reading the label.

Is there anything specific to look for to get a retro-sounding, period-authentic signal flasher?

I found this one but the reviews are mixed. I do NOT want it loud for the sake of loud, so I don't want a beeper electronic one. I'm more looking for one made the same WAS as 40 years ago. There's a huge difference, for example, between a key minder or horn relay of 1970 and a 5-prong relay of today. They're tiny inside now!