KALLAX Shelf unit with 4 inserts, white, 303/8x577/8" - IKEA
KALLAX Shelf unit, white, 44 1/8x57 7/8" - IKEA
Amazon.com: ReplacementScrews Hardware Kit Compatible with IKEA KALLAX 4 x 4 Shelf Unit 003.601.44 - All Screws (104321) and Dowels (101339) : Home & Kitchen