Hohong
Hohong Door Pivot Hinges, Heavy Duty Pivot Door Hardware for Hidden Door Bookcase Hidden Door Hinge for Wood Secret Door 360 Degree Rotation 304 Stainless Steel Invisible Pivot Hinge System
HBL'
Heavy Duty Pivot Hinge Set for Wood Door - HBL' Stainless Steel Hidden Door Hinge with Door Ball Catch for Secret Door, with 360 Degree Rotation, Invisible Pivot Door Hardware for Bookshelf.
GBGS
4Pcs Door Pivot Hinges Heavy Duty Hinges for Wood Doors, 180 Degree Shaft Stainless Steel Top and Bottom Set Pivot Hinge System,Screws not Included
Aglehome
Aglehome Door Pivot Hinge, Hidden Door Hinge for Wood Secret Door Heavy Duty Pivot Door Hardware for Max 300 Lbs Hidden Door Bookcase 360 Degree Rotation Stainless Steel