This modification to zen cart will allow you to choose up to 6 other products that you would like to show up under the product description to cross sell products.

So, for example, if you have a Laptop Computer that you sell, under the product you will have a box that says... May we also recommend... (or whatever you want to say)... then it will list other products you choose to show - like a mouse, a keyboard, cables, software, etc etc.

Works with Zen Cart Versions 1.3.9, 1.5.0, 1.5.1, 1.5.3, 1.5.4, 1.5.5