ShipCover is an eBay insurance plan, so it is available only if you use eBay shipping. There's a checkbox for it on the eBay shipping page, and there's some help there too, so you can read the gory details.
The turn around time is less than a week once you file a claim, at least it was for me. The thing is you have to wait until 30 days past the shipped date to file a claim. If the buyer files an "item not received" on day 20 (for example), and wins the case, you will have to refund the buyer that day, and then wait until day 30 to file your insurance claim, and then wait another 2-5 days to receive your claim.
I'm not an expert in ShipCover, and maybe it's changed since, but the fact is about a year ago I shipped a Kobe auto to Germany for $140, used ShipCover, the buyer won a case of "item not received", I refunded the buyer, and soon after I filed an insurance claim through ShipCover (you file the claim from the item details page), and was paid $140 2-3 days later.