BuyDig offers the LG Active-Dynamic Shutter 3D Glasses, model no. AG-S350, for $34.99. Coupon code "AGS350" cuts it to $19.99. With free shipping, that's $40 off list price and the lowest total price we could find. They feature Bluetooth and a rechargeable battery and are compatible with LG's PM4700, PM6700, PM6900, and PM9700 series televisions.