Are the ultrasonic range finders still legal?

Like the title says. I am just wondering this as my school dosen’t have a whole lot of money and if we want to messure distance the new range finders are way more expensive than the old ultrasonic ones, but I did want to buy one to find out they aren’t allowed anymore. Couldn’t find anything on the web about it so figured I’d come here.

Try the game manual, see R<6>
VRC Spin Up Game Manual