Hydraulic O-Ring Kit Boss Orb Fittings 245 Pieces (12 Common, N 90 Durometer Product Details The Kit Includes the Following O-Rings in Buna-N 90 Durometer: 35 - Dash 4 (#904) 30 - Dash 5 (#905) 30 - Dash 6 (#906) 20 - Dash 7 (#907) 20 - Dash 8 (#908) 20 - Dash 9 (#909) 15 - Dash 10 (#910) 15 - Dash 11 (#911) 15 - Dash 12 (#912) 15 - Dash 13 (#913) 15 - Dash 14 (#914) 15 - Dash 16 (#916) All Conveniently Packaged in a Multi-Compartment Plastic Carrying Case - Complete with an Easy to Use Sizing Chart. This kit is assembled in the USA by Beaver Island Parts Company. o-ring boss seal is a technique for joining two fluid-carrying pipes, hoses, or tubing. In an o-ring boss (abbreviated ORB) system, a male-threaded part is inserted into a female-threaded part, providing a mechanical seal. The female port has a straight thread and a machined surface to provide a smooth, flat, accurately located surface (minimum spotface), along with a chamfer where the O-ring seats. The seal is created when the O-ring is compressed into the chamfer when mating the male and female connection providing a leak-tight seal. High Quality Buna-N 90 Durometer Material (Also Known as Nitrile or NBR) has Excellent Oil Resistance, as well as Superior Resistance to Weather and Tearing. Buna-N Nitrile O-rings in 90 Durometer are Heat Resistant up to 212F and 250F Intermittent to -30F. 90 Durometer O-rings have a Harder and Denser Consistency and are Typically Used in Higher Pressure Applications 12 of the Most Common Sizes of BOSS (ORB) O Rings are Included ? a Total of 245 O-Rings. An Excellent Value Used for Sealing Straight Thread Tube Fittings (BOSS Type) in Hydraulic Equipment. Boss Tube Fittings are Frequently used in Hydraulic Fittings, Hydraulic Pumping, Pneumatic Motors, Cylinders, Pumps, and Valves A Convenient Sizing Chart is Printed on the Inside of the Case for Easy Identification and Selection. The Carrying Case Features a Multiple Compartment Design for Segmented Storage. Perfectly Sized for Storage in a Tool Box or Vehicle. Assembled in the USA by Beaver Island Parts Company. A Small Business with Multiple Decades of Experience in the Industry 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.