Brand New Genuine Klipsch K1027NV or K-1027-SV 5.25″ Woofer used in RB51 and other models. 4 ohm.
➡ This speaker is now obsolete. You can use the RB-51 II woofer #1011955 as a replacement. The only difference is the RB-51 SI had a shielded magnet and RB-51 SII does not. Visually, the Series II woofer has a bit larger dustcap.