Tri Lynx 00018 Wheel Stop/Chock, (Pack of 2), Orange

New to camping. Have a 5th wheel. can these be used alone to "chock" the wheels or can they only be used with the levelers ?

How many are in the package? The listing states 2 but below that it states 1. Which is it?

After a tire is on the leveler up against the rear chock, can the front chock be placed to always tightly secure the tire?

I recieved lynx levelers and not the lynx stop chocks i ordered. What do i need to do?