You are allowed to upgrade shirts (women's, hoodies, etc) but those will incur an additional cost. The discount is for our basic men’s t-shirts. You still get the discount of $45 if you upgrade, just pay the upgrade costs. That additional cost is noted next to the chosen color, style or size you upgrade to. Grab bag and discount rack items are not included in this promotion. Only 1 promotion can be used per order. Shipping costs are not discounted. If you don't choose 6 shirts, the discount will not be applied. you won't get them. We will not send you shirts later, it would be impossible to keep track of the changes. Please email us with questions! Max 12 shirts per order. If you want to order more than 12 shirts, you may do so, but it needs to be a NEW order. You can't put 18 shirts in the cart and checkout. Any discounted shirts in the cart do not apply towards this deal. International customers can take advantage of this deal! This promotion can end at any time, so buy now! Thanks!