Slider Resolution issue

The theme was awesome and I loved it and getting good response from the viewer too. my website is https://www.icomdroid.com the problem or issue I am facing is slider resolution….I need to fix the max-height 450px buh the resolution is changing its size according to each slide. I put some code on css to but its not effective. Would you plz redirect to exact css line and code for fixed resolution or maximum height ?Thanks in advance I will be hearing