https://www.cisco.com/c/en/us/td/docs/security/asa/hw/maintenance/5506xguide/b_Install_Guide_5506.html
Cisco ASA 5506-X, ASA 5506W-X, and ASA 5506H-X Hardware Installation Guide - Cisco
Cisco ASA 5506-X, ASA 5506W-X, and ASA 5506H-X Hardware Installation Guide
cisco asahardware installationxguide