Cheap And Discounts Realtek RTL8723BE Mini PCI-E Wifi Wlan Bluetooth 4.0 wireless card for E440 E540 S440 S540 FRU: 04W3818 04W3813 Wholesale. Buy Directly From Merchant WDXUN. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.