This is a totally immaculate, unused HPF pedal by Josh Broughton. New amp means I don't need it after all.  It has been discussed at length on BC and talkbass and I can confirm it is a very well made device that is as clean as a whistle.  I recently bought it new and had it shipped to the UK at a total cost of about £120 so if anyone wants one this is brand new and will save you about £25 - £30 quid.  £90 posted to UK mainland.