Pen brick resin casting mold. This will create a slab that you can cut 5 equal 1" pen blanks that are 6" in length. 
 
This mold also has an adjustable lid to hold down the objects inside the mold. If you have ever tried to cast with something that floats. This mold is for you.
 
Note: will only fit 2.5 gallon pots in a horizontal orientation. Fits in 5 Gallon pots perfectly