(Certified Scuba Instructor at Scuba.com)
Hello Melinda, Thank you for your inquiry! The XS Scuba Tank Valve Hand Wheel does not come with a washer and nut. You would use the existing parts from the current valve handle you have. http://www.scuba.com/scuba-gear-225/042317/XS-Scuba-Tank-Valve-Hand-Wheel.html
If you have any questions or wish to place an additional order, please call us at 1-800-247-2822 or 949-221-9300.