Note: It is suggested that you replace your air filter when it shows any signs of discoloration. Do not try to clean or run sanitizer through the filter, it will damage the filter. Fit for ----Airlock: The most common use might be as an airlock on any kind of fermenter. Unlike other small sanitary filters, this unit fits perfectly into a stopper. Works great for conical fermenters where displacement air is taken in when samples are taken or tub is dumped. Using the sanitary filter as airlock also eliminates the concern of drawing air back in as hot liquid cools and contracts in a fermenter. Not appropriate for long term storage of beer or wine as it is not an oxygen barrier. Fit for ----Hand Pumps: Some breweries use this filter with the breweries hand pump system. Air going back into the cask is sanitized through this filter. Package Include: 5 * In-line Sanitary Air Filter. Shipping 1.If you need to buy in bulk, please contact, we will reply in 24 hours. 2.We are always working hard to ensure your package arrives as soon as possible. Please understand that some factors like weather, high postal traffic, and the performance of shipping companies are outside of our control. 3.Usually product Reaches after about 12-45 business days depending on destination. If you have not received your shipment within 45 days from payment, please contact us. We will track the shipment and get back to you as soon as possible with a reply. Refund or resend product will be offered if item still not received. 4.We maintain high standards of excellence and strive for 100% customer satisfaction! Feedback is very important. We ask you contact us immediately BEFORE you give us neutral or negative feedback, so that we can satisfactorily address your concerns. It is impossible to address issues if we do not know about them! THANK YOU :)