Emission Labs 300BXLS Vacuum Tubes. These tubes come in "matched pairs" and are provided with a one year warranty. All tubes are personally checked by us on our Hickok 533 & Amplitrex tube testers, as well as tested in one of our many amplifiers under REAL WORLD CONDITIONS before being shipped to the customer. Please "click" for additional information on the COMPLETE LINE OF EMISSION LABS VACUUM TUBES(5U4's, 274's, 20 & 30,2A3's,45's,all 300 series(including the NEW 300B Meshplate)520 and 1605.Methods of payment are Paypal and Certified Check. Personal Checks are held until they clear with the bank.Please email your questions to either firstname.lastname@example.org or email@example.com, or call us at 516-902-3334 for any questions relating to our products. Our website is tubesusa.com. Come and see why we are held in the highest regard by our customers. TubesUSA is an authorized dealer for Emission Labs, Western Electric, Gold Lion, Tungsol, Electro Harmonics, JJ and KR Audio vacuum tubes. We also carry the finest in electronics, materials and components for the Audio & DIY community. TubesUSA.... Putting the word SERVICE back into CUSTOMER SERVICE!*Paypal customers please add 3 1/2%**Amplifier picture is for illustration purposes only, and not included in the sale. Come visit us on our TubesUSA Facebook page.