1. Using PC not easy to wear, . 2. Remote distance is more than 8M (different machine types, different distance). 3. Suitable for -071 VSX-321-K-P VSX-42 VSX-421-K SX-319V SX-319V-K VSX-321 VSX-321K-P VSX-420-K VSX-421 VSX-519-V VSX-519V-K VSX-520 VSX-520-K VSX-521 VSX-521-K VSX-522 VSX-522-K VSX-523 VSX-523-K VSX-524 VSX-524-K VSX-819H VSX-819H-K VSX-821 VSX-821-K VSX-822-K VSX-823 VSX-823-K VSX-921 VSX-921-K 4. Low power consumption makes the power is enough to operate in a long distance. 5. This remote control with full functions and comfortable bring you enjoyment to the fullest extent. Condition: Size: . 210 x 49 x 20 mm / 8.2 x 1.9 x 0.7 inch Battery Model: 2 x AAA Batteries (NOT INCLUDED) Weight: . 300 g Color: black Package Contents: 4 x Remote Control Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.