You can check the balance of your gift card by creating and account on IRONMANSTORE.com, proceeding to the 'My Account' page, and then selecting 'Gift Card' from the side navigation. From there, enter the code in the box and select 'Check Status And Balance':
Alternately, you can redeem the gift card and add it to your account as store credit by selecting 'Redeem Gift Card'. This will add the gift card amount to your account as store credit.