Anyone have the type of sail covers that is attached to the boom?

I like to single hand Redcloud all the time, but hate stacking,
flaking the main sail.

I installed Lazy Jacks but want to incorporate them into new sail
covers that attach to the boom and rool up on each side when not in
use.

Has anyone used this type of system? How is the top of the sail
covered, is there a velcro flap?

Anyone know of a drawing or description anywhere online?

Thanks

Joe