>>510516920
the best is when imported from china these are like 500 EUR (~580 USD), costs like 3 EUR a day to run (3.50 USD) and can be replaced without any issue. same if you move, you just move it with you, you only have to replace the velcro for the covering. exhaust hood is also a way to connect them in case you live at ground level and dont want to have an open window due to burglars