The SSM2044 is a classic 4-pole lowpass filter chip, as used in a large number of great synths, including the PPG Wave 2.3, the Korg Monopoly, Polysix, and Trident, Seil Opera6 and others.
The chip has differential signal inputs, and offers voltage control of both cutoff frequency and resonance. You can find out more about how a few classic synths used the chip on the SSM2044 Lowpass filter designs page.Download SSM2044 datasheet
These are original unused vintage chips with a 8730 date code (e.g. week 30 of 1987).