18×18 MSD – Minimum Security Diffuser with 3/16″ Diameter Holes and Damper, 4-Way, Steel

For minimum-security areas, such as mental health facilities, offices, and public areas, the SMD diffuser can be combined with a lattice faceplate to prevent access to ductwork and protects pattern controllers from damage and removal. The minimum security SMD can be mounted using either security screws or an optional rear mounting plate with tamperproof bolts.