The Jeep Wrangler is experiencing a sales bonanza, outselling 25 other brands all on its own. Ford could steal some of these sales with its upcoming Bronco and Fisker has also set its sights on Jeep with some sort of removable roof on its upcoming electric SUV. But Fisker isn't the only electric automaker looking to steal sales away from Jeep because Rivian has just announced several roof options that will be available on its R1S SUV and R1T pickup truck.

A guy on Twitter who has a pre-order for the R1S asked the company if the glass roof he's seen on the pre-production car will be fixed (like a Tesla Model 3) or sliding. The company responded with some interesting news.

"We will offer multiple roof styles including electrochromic glass (which turns from opaque to transparent on demand), a fixed glass panel, a two-piece removable composite roof, and a standard fixed roof," the company tweeted. The answer, while detailed, didn't actually answer the man's question about whether the roof opens but based on how the answer was worded, we would guess the glass roof options will be fixed.

This might be disappointing for drivers who like to open the moonroof while driving but Rivian will offer a two-piece removable roof, which might be even more enjoyable. The electrochromic glass option quite a neat feature found on other luxury and super cars from Mercedes-Benz to McLaren.

The only SUV to currently offer a removable hardtop option is the Jeep Wrangler, currently a $1,195 upgrade over the soft top in black or $2,195 for body-color. It will be interesting to see how Rivian handles the specifics of the panel operation and how they will be stored when not in use. The R1T and R1S are both expected to launch next year so perhaps Rivian will show off production versions at an upcoming auto show to fill in some of the blanks with the four roof options.