We have toppers that'll work for 2 of your 3 sliders.
For your 12 foot 9-1/2 slide, use # LCV000168109 which is designed for slides measuring between 152-157 inches wide.
The longest topper we offer is for slides 188-193-3/4 inches, so unfortunately we don't have anything that would work for your 16 foot 7-1/2 inch slider.
For the 6 foot 7 inch slider, use # LCV000168105 Ihich is for sliders 74-79 inches long.
I've linked you to a typical installation video. view full answer...