At checkout, you will prompted with a notification of your gift certificate.
As usual, you will promptly receive an email invoice of your recent purchase. This invoice will include the gift certificate code. Be sure to retain this code for your future purchase which is good for 1 year from the issuing date.
Upon redemption of your gift certificate, simply proceed to checkout with your order. During the "Payment and Shipping" portion of your checkout, you will have the option of entering this gift certificate code. The correct area to enter this code is denoted below by the red arrow next to the "Gift Certificate Code". Click "Apply" (next to the code you entered) to activate your discount.