These mini ornament hangers are designed to hold 1.4 inch long ornaments with a 7mm (millimeter) diameter internal holes along this axis. You can make your own ornaments using various materials, beads, or purchase compatible ornaments in this store. Unlike the A, B, or C series of mini ornament hangers the D series uses smaller threads and eliminates the sprue connection hole in the bottom cap.
The bottom cap is connected to the main hanger body with a small looped sprue that you need to cut off. Connecting the parts in this way reduces the cost by eliminating multiple parts handling charges at Shapeways. Cut the sprue with a pair of small wire cutters or a strong pair of scissors where the screw thread ends. You may need to sand the sprue remnants flatter for a proper fit.
It is likely that residual powder from fabrication will be present within the screw threads and you won't be able to screw the parts together until this powder is removed. An easy way to remove this powder is to slowly screw and unscrew the two parts together in a bowl of water or under a low stream of water from a faucet, rinsing out the threads between attempts as the powder is loosened. It only takes about a minute to do this and once the residual powder is gone the cap should screw flush with the main body of the hanger.
If you want a permanent assembly you can use a small dab of glue on the screw threads to keep the cap in place on the hanger body.