I had a significant problem with a large quantity of GU10's purchased in 2015. Even with a 5 year guarantee I thought I would be 'p88s*-&? in the wind'! However, just one email to LED Lighthouse and a new supply came my way. Effortless. What a pleasant surprise that a company goes to this level of customer satisfaction in these new days of limited, difficult or impossible contact/communication. Tremendous.