"Xtenzi Brand External Remote knob XTBR3AS bass Boost Wired Variable Level Controller (secondary gain control) ,Includes Bass Knob, Cable. , Compatible with Select PowerBass amplifier like, ASA400.4x , ASA-400.4, ASA600.4x , ASA-600.4, ASA300.2x , ASA-300.2, ASA400.2x , ASA-400.2, ASA600.2x , ASA-600.2, ASA800.2x , ASA-800.2, ASA400.4x , ASA-400.4, ASA1100.5x , ASA1100.5, ASA700.5X , ASA700.5, ASA1000.1Dx , ASA-1000.1D,SA1500.1Dx , ASA-1500.1D, ASA400.1x , ASA-400.1, ASA1200.2X,. Make sure the remote is compatible with your amp before purchase. Not all amplifier will be properly control with this item. Important Note:Above mention Accessory/Product is a Xtenzi Brand to help consumer find the correct Part all brand names listed are compatible with the referenced product or technology only."