Post is a 4 x 4 (.50)
Top is a 2 x 4 (.25)
Bottom is a 1 x 4 (1.00)
Bungee is attached to hook screws on the top and bottom boards. Bottom board is attached to the 4 x 4 post and buried about 3-4 inches (more if your post is long enough). I ran the bungee through a golf ball and have another bungee (on the ground in the pic) with a real baseball. Can also be modified to include a softball as well.
This is just like a tee except you don't have to chase or pick up balls. Plus, if you open your hands too quickly, the bat will bounce back. This forces the hitter to keep his or her hands inside and follow through.