You could help out just a bit by providing as much info on them as you can. There is no size reference on them..they could be two inches or ten inches long. Are those spring clips?

One end looks like a clip. Is that so?
I have no idea what they are, but here's your picture...maybe someone else will know.
Linda C

Here is a link that might be useful:

I might be crazy, but I think it goes in a coat-check room; the flat tab goes in the buttonhole of the coat, and you use the clip for the hat; thus, the gent's hat & coat are kept together.
Casey

How about from a coat check room at an eatery called "The Derby" at a racetrack?

Absolutely!!

Its actually a cuff holder...
I was able to find one online... here is the link!

http://www.etsy.com/listing/65222052/antique-cuff-holder-circa-1898-the-derby?ref=sc_1

I have no idea what they are, but I'm a bit skeptical about the cufflink holder idea. They very well may be, but for the life of me, I can't figure how they would be used as a link holder, or why anyone would want to use them in conjunction with cufflinks. I could see using them to store your links with a particular shirt... the button hole idea previously posted and using the upper H shaped device to hang your links in.. but what is the clip for? That being said... was it common to hang particular links with a particular shirt? Or for another, I don't know that I would want to hang my nice links metal to metal with a device like that.

As a coat room check device... I can kind of see it... sure seems to make sense, but then again, back in the day there was usually a segregated hat shelf for the purpose, and the clip looks a little "harsh". Meaning.. the spring looks pretty strong and the clip isn't padded in any way. I wouldn't want clip marks on my hat.

The hat clips I think more about are those gentler looking clips on the back of church pews. KWIM? You would push the button to open the clips and they often had fabric covers on the "teeth" of the clip so it wouldn't leave marks in your brim.

All told... darned interesting little items there! Quite fun to speculate about, and whatever they are.. they sure seem to be in very nice condition. If it were me.. the horseshoe says Vegas or the horse track. I would try and look into any old horse track museums or archives to see if anything clicks.

Thanks for all the help....I think we're on to something. Mikk, the link Raetaylor gave said it was a cuff holder, not a cufflink holder. But, why did they have detachable cuffs? I'm not sure that's really what they were. I think the hat idea is better, but I agree the clips are pretty "harsh" for a hat. I think I'll keep looking, but if anyone else has ideas, I'd love to hear them. By the way, they are almost 3 inches long.

Raetaylor said they were cuff holders and provided a link...from there to cufflinks?
Back in the 'olden days" men's shirts came with detachable collar and cuffs....the shirt was worn more than once before washing but the collar and cuffs were replaced. I think the picture which suggested they were cuff holders didn't know what he had either and just guessed.
And I am not totally sold on it being a hat check item....why is the clip sideways and not straight down? Perhaps the clip hooks on the hanger, the "H' shaped thing is for a scarf and the button to hang the hat on.
Just a guess....

Looks like they are cuff holders.

Vintage 1889 Wizard Cuff Holders Gambling Cheaters Clip

and

antique cuff holder, circa 1898 , The Derby, with horse shoe detail

and

3 Antique Card Holders Cufflink Sleeve Clip

Ahhh... detachable cuff holder. Sure looks like it. Thanks for the links chemocurl :-)

Must have been childhood memories. My grandmother always used to call grandfathers links "cuff holders". That must have popped in my mind before "detachable cuffs" did. My bad.

That big H on the end sure does look to be uncomfortable though. I can see how it might help stabalize the cuff, but I wonder if it's unique design had any other purpose.

I have done quite a bit of research on edwardian and victorian era clothing and some of the cuffs and collars men wore were quite substantial. Some even made of early type plastic. Some were double cuffs and ornate, depending on the occasion or time of day. So these could have been to hold something that had quite a bit of weight. On second glance seeing it said "the derby" with a horseshoe... maybe these were some type of cuff holders worn or bought at the Kentucky Derby... where fancy dress is the norm.. especially in 1898?

Also alot of people thought these were made for hiding cards in ones sleve to cheat at cards. Although that may have been a plus to wearing them it was not their design purpose.

I just found this intresting!

http://cardshark-online.blogspot.com/2010/01/little-card-holdout-that-never-was.html

Great link....interesting read....and we all learned something!

raetaylor - Extremely interesting! Thanks for sharing.

Now... we play on Monday nights... where can I get me one? LOL