Im pretty sure they don't. I thought it was only the Stellar range that was S fit?
No defo not...they come with a softbox (ex150 set) stands & brolly...
I bought a set at Xmas as I had a jessops voucher...you can squeeze a grid into the reflector (Claumet)...
I really bought them for my (FITP) Hilite...and rear lights...and they do the job...
I am looking at Quantuums just now...and the two head 300Ws kit is well priced (Ebay) also there are people on the forum using them (the battery version) and there is a mini review of them...
Dont know if this helps...
STEVIER