here are many planners out there, but I'm convinced that most of us can plan our whole lives in the modestly sized Hippo 6-Ring Planner. Small and portable, it has three tiers of card slots, a checkbook retainer strap, and a sturdy ¾" ring binder that fits standard fillers widely available at office supply stores (fillers not included). My pen clasp closure keeps your planner closed, and you always have a pen handy when you need it. Fits standard 5"x7" fillers from Dayrunner, Daytimer, Franklin, Rolodex, and others. Lifetime warranty.