looks like rovan are stopping there roller and making it the ARTR as there roller link is no longer available
https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjx2a_ZwY3KAhVGPhQKHe9rC5kQFgggMAA&url=http%3A%2F%2Fwww.rovanrc.com%2F1%2F5-truck%2Flt305-4wd-short-course-truck-roller-clear%2F&usg=AFQjCNGwUlYfe-4dMRIEkpbGMMwMrvx7Jg&sig2=ISvdXp5EqYOV64B0Dn4_NQ