These are the Ultrasonic HAL-O 27 in nickel alloy, which I bought for my EL34s. The website is here: \r\n\r\n[URL]http://herbiesaudiolab.home.att.net/[/URL]\r\n\r\n(Search this page for "EL34" and you'll find them straight away)\r\n\r\nThese tube (sorry, valve) dampers work exactly as claimed on the website - I certainly can't complain that they don't perform as stated. Unfortunately, for my tastes they are a little too detailed. Call me old-fashioned, but I missed the slight fuzziness; so off they came. \r\n\r\nThese dampers (there are 4) have had a total usage of under 6 hours on my system. As far as I'm aware, they're only available in the US. The new price is .80. This works out as £27.18. With VAT that's £31.93, plus whatever else Customs decide to add on, plus shipping from the US. You're probably looking at £35+.\r\n\r\nI'm asking £25, which includes recorded delivery to anywhere in the UK. \r\n\r\nPlease pm me if you're interested.