One online supplier I usually buy from lists the DS125 strobe package as having a
#4085.51 Deluxe ball socket arm system

the other lists

#4085.61 Deluxe ball socket arm system

IS one better than the other??

There was a #4086.51 comprised of 1.25" arm system components. Better holding but current #4086.61 is preferred............

http://www.ikelite.com/web_pages/arms.html

http://www.ikelite.com/web_pages/ds50_pkg2.html

Thanks, gotta go get that visa