The Bubble-Lok design pops open easily with the push of your thumbs yet your pills are stored securely when it is closed. The 7-Day Ultra Bubble-Lok? XL Pill Organizer features a unique patent-pending locking system that simplifies operation and prevents pills from spilling inside your briefcase purse or suitcase. 2 sizes available ??? large and x large. Contoured compartments for easy pill removal. To open any compartment, use thumb to simply push on the contoured Ultra Bubble-Lok wall area on the front of the compartment and the lid will pop open.