They probably used either Fleetguard or Fleetcharge. As mike noted, your best bet is to call them and they will give you the scoop.
I had them do a coolant flush, refill along with new hoses and a coolant surge tank last year. I asked them if I needed to add antifreeze would Fleetcharge (already mixed...no need to add water) be OK to add. They said yes.
'07 Country Coach Allure 470 Siskiyou Summit #31578, Cummins ISL 425; 2014 Ford F150 toad; Air Force One Toad Brake.
Glen Allen, VA; Smith Mountain Lake, VA.