Containers that feature an audible 'clicking' sound when the leak-proof seal has been properly engaged, assuring accurate closure and maintaining specimen integrity during transport.

• Designed to eliminate leaks occurring during specimen transport.
• 100% virgin medical grade plastic provides consistent vial-to-vial performance
• Audible proof of closure confirms engagement of leak-proof seal
• Cap designed to enhance seal during positive and negative pressure differentials
• Textured edge on cap offers an easy gripping surface for users