Fuutreo 4 Pack Bookcase Connector Compatible with IKEA Billy Bookshelf, Shelf Aligner and Straightener for Seamless Library Look, Black Petg Top Bracket for Gap-Free Alignment and Stability

["Bulk 4-pack Value: this 4-pack bookcase connector set provides ample replacements for multiple shelving units, keeping every connection stable, secure, and perfectly aligned for long-term use; Compatible with IKEA Billy bookcases, offering a fit for repairs, upgrades, or custom configurations","Professional Built-in Library Look: create a seamless, built-in library appearance by combining separate bookcases; These shelf aligners eliminate messy gaps and keep shelves flush for a clean, high-end custom look","Black Petg Material: made of sturdy and flexible black PETG, these shelf straighteners deliver excellent durability and resistance to breakage, maintaining reliable holding power for long-lasting use","Easy to Use: no tools, screws, or drilling needed; These top brackets install in seconds by snapping onto the top of your bookcases, making assembly fast and seamless","Stability Gap-free Alignment: effectively prevent shelves from tilting or separating; Our gap-free alignment design reinforces stability, keeping your entire bookshelf system straight and neat at all times"]