I just saw these at FastTech and thought I’d share:
http://www.fasttech.com/products/1/10004194/1316201-eight-character-shape-plastic-buckle-clasp-keychai
I bought 2 of these on ebay for $2.20.
They feel hollow but are reasonably sturdy.
Tried one on my keys for a week, but the opening was a bit small so I went back to a medium D biner.
Grabbed a couple of these off ebay years back when I couldn’t find any reliable carabiners in retail stores. They are mini versions of climbing carabiners.
http://www.ebay.com.au/itm/250814341173?nma=true&si=p6WTRYGQ5yPEq%2FgsEjGxNFK%2FydU%3D&rt=nc&\_trksid=p4340.l2557&orig_cvip=true#ht_1155wt_1085
They are 50mm from top to bottom, rated at 150kg, don’t have an annoying hook on the opening that snags and the clip doesn’t bend off to the side. what more can I say 
Still on the first one too :bigsmile:
Have used one for over a year on keychain and its still as new
They are called le hook and swiss made.
Very handy for splitting keyring or adding extra keys
Found these at ring lord
Lots of colors , lobster claws in tI , plated, powder coated, etc. Even copper.