Yes, first read all of the information posted by the seller on the product listing. If you still have questions then you may ask the seller a question.
To send your question directly to the seller, simply go to the product listing you have questions about and under the section 'About the Seller' is a link that says 'Ask *username* a Question'. Click on that link and then fill out the form with your questions and then click on Send Email. After that your message will be sent directly to the seller's email address.
When the seller replies it will go directly to the email address you provided CPAPAuction at registration, so be sure to check your email regularly.