Using this lint filter is easy. Just install it in your Haier HWT90MW1 or HWT90MW2 top load washing machine as per the machine's manual. It will catch lint and debris during the wash cycle, keeping your clothes cleaner. As for maintenance, regularly check the filter for lint buildup. When it gets full, remove the filter and clean it under running water. Make sure it's completely dry before putting it back in the machine. Also, if you're unsure if this filter is right for your washing machine, reach out to us with your full model number before making a purchase.