Keep your busy schedule secure in this calendar base. Two rings lock in a loose-leaf calendar refill (sold separately). Features a classic yet contemporary look. High-impact, molded plastic base provides long-lasting support and is recyclable. #17 Calendar Base—Standard base fits most looseleaf calendar refills up to 3.5 x 6. Size: 3.5 x 6; Color: Black; Material: Molded Plastic.