www.dogcatsupply.com

This puzzle is a clever and inventive plastic version of Nina Ottosson's original  wooden Dog Brick which lets you hide your treats in recesses located under a series of interlocking sliding blocks. Since the blocks can not be removed, your dog is required to locate the treats by sliding the blocks with either his paw or his nose in order to retrieve his reward. This version also includes 4 plastic bone shells which can be used to increase the difficulty of the toy by adding an extra impediment. The plastic construction is light-weight and dishwasher safe.  Includes training guide.