Removing additional menu icon on header

Hi, How can I remove an extra menu icon/button on the header right side of my website? In addition to my standard menu button (which usually comes when using tablet or mobile), I have an additional useless black-coloured menu icon/button on the header right side of my website which I cannot remove it. Please check it on www.futureoutlooks.com and kindly let me know how I can remove it. Thanks,