a.k.a. Hole In One
Left circa 2000?, right "Hole In One" purchased 2007.
(Slider has aluminum tray and 5 aluminum pieces, 3.25 by 4.5 by 3/4 inches,
Hole In One has wood tray and 5 wood pieces, 4.5 by 6 by 1.25 inches,
directions added by J. A. Storer to Slider box top and Hole In One box bottom)

Move the 2x2 square inside the L's as shown by the figure on the right above. Here is the solution that came with Slider (the solution for Hole In One is identical except it says "Hole in One Item #07-7821" at the top):