Fanstel 2-Line Business Professional Amplified Speakerphone (ST250) Conference-Grade Speakerphone - Up To 83 Db Spl At 20" Up To 52 Db Amplification At 120 Db Spl Frequency-Specific Amplification For Both Handset & Headset Conference-grade speakerphoneup to 83 dB SPL at 20-Inch Up to 52 dB amplification at 120 dB SPL Frequency-specific amplification for both handset & headset Auto-selects the best amplification level RJ22 & 2.5mm headset ports