Triplette FIE Stretch Underarm Protector

Weighs almost nothing, and wicks like crazy. It is remarkably cool and comfortable. The fabric is just stretchy enough, and a good fit with the three elastic straps.

It's not padded, but good protection with FIE-level 800N fabric, and all US-made - fabric and manufacture. Price is reasonable, and fast service by Priority Mail.

http://www.triplette.com/catalog.php?item=20

This has been such a pleasant item to wear that I don't mind wearing it at all. 

In fact, I like the wicking and breathability of the Spectra fabric so much that I've ordered an entire custom-fit uniform made from it from Triplette.