Designed by Wayne Daniel, made and sold by Interlocking Puzzles, 2003.
(Paduk and Maple, 4 pieces, 3.5 inches)
Two pairs of identical pieces slide together simultaneously.
The solved puzzle has a maple diamond on each face where one point meets the point of a diamond on an edge shared with an adjacent face.
Here are views of the start of coming apart,
and the four pieces:
To solve, as shown on the left below, determine how to assemble two halves that are in the solved state,
spread each apart to just coming apart, and with one par in each hand position carefully so that everything can be pushed together.
The photo on the right below shows the side not shown in the photo at the top of this page.