Mann McGowan DD-1703ACU, is a robust twin adjustable threshold seal which allows the drop mechanism to be adjustable at both ends for both downward movement and tilt control to provide strong even pressure over the entire length, so providing an enhanced seal which can be fine tuned to suit the environment it is designed to operate within. DD-1703ACU will provide acoustic, cold smoke and environmental sealing when used in conjunction with suitable doors and has achieved a 60 minute fire rating when tested to BS 476 pt. 22 1987.