3.5mm TRRS female . 4P4C male plug Use your existing i Phone/ P a d, or similar TRRS headset with your -based phone Avoid having to purchase an expensive headset Great businesses, offices, call centers, and more Eliminates the need to have more than one headset For IP phone headset for models: 6921, 6941, 6961, 7931G, 7940, 7941G, 7942G, 7945G, 7960, 7961, 7961G, 7962G, 7965G, 7970, 7971, 7971G, 7975, 7975G, 7985, 7985G, 8941, 8945, 8945G, 8961, 8961, 9951, 9971,etc. P LANTRONICS M10, M12, M22 & MX10 Vista. and high quality! Type: 3.55mm earphone to RJ9 phone adapter Color: Black Material: ABS+PC Length: 31cm Package Contents: 1 x Headset to RJ9 Cable Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.