Bought there is approximately 1 year. Its very good (excellent price-quality ratio) and arrives at a driver without difficulty high impedance headphones. For cons, the case is extremely sensitive to interference from nearby electronics like mobile phones, wireless mouse, baby phone, etc. It is necessary to remove several meters disruptive elements. I thought my STU was an isolated case, I therefore requested an exchange at Amazon (which has also been done very quickly) but the problem persisted. I also tried on different PCs (fixed and portable with and without grounding).