You are provided with a total of 160 diapers. Week 1 will give you 80 diapers. Week 2 will give you 80 diapers. Week 3 and on will give you back only the diapers you've used two weeks prior. Say you have 80 but only used 67 on week 1 and are given 80 but only use 72 on week 2, week three will give you 67 back and pick up the 72 you've used. Week 4 will give you the 72 you've used in week 2, and will pick up what you've used that week. The rotation continues until you don't need our services anymore.