I have used this system for approximately 15 years.  We have several trailers, and of course they have different hitch sizes.  This system makes it so easy to change the ball.  I have this system on all three of our trucks.  My daughter pulls her horse trailer almost on a daily basis.  Then we hook up to the flat bed for getting hay.  She changes the ball and away she goes.  I have purchased several of the kits and gave them to friends for gifts.  Sure beats trying to find a wrench to change the ball. If you have this system you will always have the right size ball with you.  I use the plastic holder. It keeps the grease  from getting all over.  I have a small Phillips screwdriver to help push out the pin. I am going to purchase another set at the Tulare Ag Show this February.  Never had a problem with them.