SC13 Aggregate.Org/UK Dovetail Puzzle Keychain

In our Aggregate.Org / University of Kentucky research exhibit at the IEEE/ACM Supercomputing 2013 conference, we had a number of 3D-printed things in the exhibit or used as giveaways. This is the little dovetail puzzle keychain that we made as a giveaway to remind people of how our SWAR (SIMD Within A Register) and LAR (Line Associative Register) technologies work. The dovetails on the top and bottom appear to interlock such that it would be impossible to take apart... which it isn't.
SWAR & LAR are computer technologies in which registers are partitioned into fields that are operated upon in parallel. We also have posted a blank version of this puzzle keychain for folks who don't care about SWAR & LAR but like the apparently impossible dovetailing.