Plantronics 15729-05 Ear for H51, H51N, H61, H61N, H91, H91N, H101, H101N, SP04, SP05, PLX400, PLX500, Black Part # 15729-05 is sold as a pair of ear cushions and simply slides onto the speaker of the headset. Material: Foam Compatible with: H51, H51N, H61, H61N, H91, H91N, H101, H101N, SP04, SP05, PLX400, PLX500