Optimise CSS Delivery

I Have Master Slider on this Page http://totalsurfacetreatment.com/บำบัดน้ำเสีย/บริษัท-บำบัดน้ำเสีย

But when i Check Page speed Insight on other Pages I still get Optimise CSS Delivery of these 2 Master slider Related

1) plugins/master-slider/public/assets/css/masterslider.main.css?ver=3.1.1
2) uploads/master-slider/custom.css?ver=3.2

As I have also not checked the Load asset on all page in advance setting
I dont Seem to know the Solution

Apart from that a Fantastic Plugin
Appreciate all the Help, Thanks

The page I need help with: [log in to see the link]