found one on Siemens web site. it says it is listed for 3 1 pole breakers as a pad locking device as well as a tie
http://www.sea.siemens.com/us/Produ...uit-Breakers/Pages/Padlock_Device_ECQTH4.aspx
Here is a copy & paste from the instruction sheet: "Note: Not for use on three phase circuits."