How to determine the Custom Field (Array) for a Custom Field?

[R-n-R]

I added a custom field in one of my products and when setting up a custom Email Template for this product I am wanting to pass along the value of that field in the email sent to customer.

 

I am assuming I should be using the following

Custom Fields (Array) {$client_custom_fields.1}

 

My question is how do I determine the particular value "{$client_custom_fields.1}" for the custom field I created in a specific Product/Service?

 

Thanks for the help!

[lanesi]

This is also my doubt. Someone can help us?

Thanks.