AudioQuest : SureGrip 300 BFA/Banana 

SureGrip 300 connectors use Direct-Silver Plating over our high-quality Beryllium Copper base metal. SureGrip 300s use no underlying brass layers that would inevitably cause distortion and otherwise damage the sound. SureGrip 300s employ our effective Cold-Weld attachment system and feature an attractive non-metallic POM casing.