These filament units were used for a minimum of two hours and were then removed from systems to be replaced with a different filament type.  This item is priced accordingly. 

• For gas-tight ion source of QMA 200
• Cathode unit, tungsten
• 2 filaments
• Order part number BN846281-T
• Manufacturer warranty included
• Used condition, each filament was used approximately 2 hours in the Bay Instruments lab
• Sold only to end-users in the USA and Canada
• Condition:  Used no more than two hours