By using the Sites, you agree to such terms and conditions. &nbsp;<br> <br> If you are under 13 years of age, do not use the Sites.&nbsp. If you are under 18 years of age, you may use the Sites only if you have legal parental or guardian consent to accept these Terms &amp. Conditions and are fully able to abide by them. To the extent that you purchase any products or services or participate in any contests, sweepstakes or other promotions via the Sites, you warrant that you are over the age of 18, have the right and authority to enter into these Terms &amp. Conditions, and are fully able and competent to abide by them. If you are not over 18 years of age, do not purchase any products or services or participate in any contests, sweepstakes or other promotions via the Sites. Sierra Club does not knowingly collect information from children under the age of 13. If you are under 13, please don't submit any personally identifiable information to the Sierra Club on the Sites.<br> Contents:</p> <ul> <li>