Here you know you're getting new tubes that will last a very very long time. The NL 5441 is not being manufactured, so when all the vintage supplies are exhausted they're gone forever. Get some while you still can.See our other auctions for many more tube lots. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Parts & Accessories\Vintage Tubes & Tube Sockets". The seller is "jdmsales" and is located in this country: US. This item can be shipped worldwide.