Props like models, toys, or samples of a product can work wonders if you need to explain something concrete or sell a product.

Don't pass around a sample or other prop unless you are going to be talking about it then. These things can distract the audience from your message if allowed to float around endlessly.

The idea situation is to either pass out samples at the end of a presentation, or have them passed around the table so they come back to you. Either option helps keep the audience focused on you.