Source 1 / York 7681-3231 Motor-Damper Compatible with models S1-7681-5091/A, S1-7681-3231 and 7681-8191/A Compatible with models 7681-8191/A, 7681-8191 and 7681-8171/B Compatible with models 7681-8171/B, 7681-8171/A and 7681-8171