Would suggest that they are the same thing. I understand that the impuls ones are the original German version. I believe that the roller ball are the copies eg by Mark Todd etc.
I will happily be corrected if this isn't the case but it's my understanding
I'm with loves_orange thinking that they are basically the same
I have the Mark Todd ones and from what I can remember looked the same as the impuls ones in the shop
Well that's what I thought until ................ having looked on the Inch's Saddlery website. There are the spurs we all seem to know and love with the "black ball ends" and then further down the page a spur termed "Steel Roller Ball" and that looks different - and that is where my confusion is setting in because of the name "Roller Ball"!