Since Ikea discontinued the Algot series of wire baskets and storage system in 2020, no replacement parts are currently available. But if you're moving you might need more of these brackets that you've probably either lost or thrown away if you didn't stack the Algot shelves on top of each other before. I've modeled these to match quite closely with the original design by Ikea. 

Printed with 100% infill in PLA for good strength and slightly higher stiffness than original. I'd also recommend printing these with “Support on build plate only” and with the “E or 3” shaped face against the build plate. Tested, works just as original and with white filament, you'll barely can tell the difference.