I'm going to be selling my used 3M air stream. The belt power pack is a problem for me to put on due to arthritis. It looks like they've discontinued making them: https://www.3m.com/3M/en_US/p/d/v000093620/ Thinking of sanitation and other issues (covid), what parts would you replace before selling and where do you purchase your supplies from. Envirosafety is a nightmare for me to navigate. I can get the chin strap but not able to put it in my cart. https://www.envirosafetyproducts.com/3m-products/3m-tychem-qc-faceseal.html