This pair of UREI / Universal Audio 509 EQ's were, as the eBay description states, designed with the UREI 1109 pre in mind. They were originally incorporated into the preamp's design via a feedback loop with the 1109's amplifier. Two-band, general purpose equalizers with boosts or cuts at 50, 70, 100, 400 Hz and 2.5, 5, 7, 10 kHz with LF (100Hz) and HF (10kHz) roll-offs. Rack them up as passive EQ's, or better yet, throw amplifiers of your choice after them to make the most of them:
UREI / UA 509 Pair