Used Panamax MB1000 Back-Up/UPS/Surge Suppressor. Removed from a system , batteries were low. I replaced the batteries, it now works great, has great run time. This unit is in great condition, the front panel and display is perfect, even though it looks like there is a scratch in the photos, there are none. This back-up sold for about $1200 new, was in an a/v equipment rack for about 2 years. The replacement batteries (2), are about $30 each online, so very affordable to replace when needed.