Venting Adaptor

I designed this 4" adapter to fit a venting hose to vent out the enclosure through a window. I use an 80mm fan and it was 12volts. I also used a pwm controller to adjust the speed of the fan so the ambient heat remains adequate. I found the controller on Amazon. It seems to work just fine.

uniquegoods 1803BKW 1.8v 3v 5v 6v 7.2v 12v 2A 30W DC Motor Speed Controller (PWM) Adjustable Driver Switch
by UG seller
Learn more: https://www.amazon.com/dp/B00RYKR83Q/ref=cm_sw_em_r_mt_dp_U_yJ6qDbVA0B6Z5