Each of the included eight pill boxes contains four, numerically marked, compartments for each day of the month. This gives you a total of thirty-one daily compartments in the most compact monthly organizer we have available. When used with our MedCenter talking alarm clock or the "MedCenter your minder alarm clock" (both sold separately), the MedCenter mini becomes our most efficient and compact organizer system add in the daily xl and the system works great for travel as well8 pill boxes numerically marked with the day of the month easy open lids on pill boxes allow for easy access to needed medications compact design makes the unit more convenient than ever our new larger xl pill boxes (used in all products denoting the "xl" size pill boxes, also available as an accessory to the existing MedCenter system) have an individual dose compartment which measures roughly 1 3/8" wide x 1" long x 3/4" deep on the inside. Each of the new xl pill boxes contain four of these dose compartments.