Interesting thing happened the other day. I use a novib socket saver to boost the height of the tube for easier swapping and to save the original socket from wear. I purchased one about 11 months ago from Tubemonger.com. The one I had started to act up so I contacted the seller, and explained what had happened. He replied that he had sold thousands of them and only had about 8 go bad. He made sure I swapped it in and out with other tubes and without novib. This was on last Friday, I sent the email in the morning, and by afternoon had heard back from him. He sent me a replacement the next day Saturday and I received it on Monday. Customer service is alive and well, with this company. He did not charge for it after 11 months of daily use, I feel good about this, that there are companies out there that still work with the customer to resolve issues. Felt he was trustworthy so I purchased a valve from him to so good faith. Just wanted to pass on this info. Don
