For Hsb Models Made Before 2013, Use The Generac 5665 Air Cooled, 999Cc Kit. Product Details Scheduled maintenance is a necessity for all standby generators. The Air-Cooled Scheduled Maintenance Kits offer all the components necessary to perform a complete maintenance on Generac air-cooled generators. Maintenance is recommended at every 200 hours or 2 years. If running in a dusty environment, more frequent maintenance may be required. Generac Guardian Maintenance Kit for 20kW Home Standby Generators Tune-Up Kit, Keep your generator running at optimum performance Contents: Air Filter, Oil Filter, Oil Funnel, Spark Plug, Chamois, Instruction Manual, Reminder Sticker (2008 to 2012) Includes: air filter, oil filter, spark plugs,oil funnel, chamois Oil must be purchased separately Includes: air filter, oil filter, spark plugs,oil funnel, chamois Oil must be purchased separately Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.