[Fot] Help Identifying this

[Jack Wheeler]

Attached is a picture of something I used on my race car a long time ago, but now I can't remember what it was for.  Any ideas?  As you can see by the fittings on the sides, it was plumbed into the brake line.  That looks like a bleeder nipple on the bottom.
If anyone knows what this is, and would like to have it, send me your address and I will mail it to you.
Thanks.
Jack
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