Windsor Hardware Halo Range - Hydra The Halo range has been designed as the ideal solution to retrofitting projects, with the large rose perfectly covering any existing 54mm holes in the door achieving a smart andcontemporary look on original doors. FEATURES AND BENEFITS Large rose perfectly covers existing 54mm holes when retrofitting Constructed from solid aluminium Suits door thicknesses of 32–55mm Single direction lever action Not for external use 54mm drillout hole x 60mm backset - 70mm backset options available Fitting Instructions https://assets.windsorhardware.com/assets/fitting_instructions/halo/Fitting-Instructions_Halo_Passage.pdf DATA SHEET https://assets.windsorhardware.com/assets/data_sheets/halo/WAH_DataSheet_Halo_Hydra.pdf