Based on this product's specifications, here are some alternatives and similar models
Binding Spine ARGO plastic 22 mm 50 pcs black (model 36K034A)
Summary description:
Plastic binding spines by ARGO, 22 mm diameter, pack of 50 pieces in black (model 36K034A). Designed for comb binding of documents, reports and manuals, compatible with standard 2:1 punch patterns. Provides secure binding for documents up to medium thickness and simplifies assembling and disassembling bound pages for editing or redistribution.