BBQ vent regulator

Clearly inspired from other designs here this vent is passive only (no fan) and is designed for slow cooking. It is quite small and made to operate with limited airflow as required for low and slow cooking on a kamado grill or similar. I use an imitation insulated steel kamado - much like the 'acorn' and this will give me more than enough air. There is an adaptor plate also I need to get a photo of up at some point but at this stage the outlet connects to a 25mm (1 inch) square (external) aluminium tube which I have then attached to a modified plate that fits to my BBQ air intake. I will re-post when I have the whole thing together - including the arduino in case to drive it (or possibly a micro:bit). This is the first part of a bigger project. Fits an SG90 servo. No supports required