Remove seat 2001 Gulf Stream Yellowstone

[esbliss]

I am trying to remove my passenger seat and am having trouble finding the proper size male Torx socket. I have tried the T50 and T55. The proper size is somewhere between these two sizes. I don't know where to start as I have contacted the local Ford dealership and thet cannot tell me. My rig is a Ford E450 if that would make any difference/
thanks

[SCClockDr]

Is it a secure torx? (Has a pip in the middle & requires a secure bit with a hole to match the pip.)

[Wayne67vert]

I bought a set of Torx at Harbor Freight. I used them to remove my drivers seat on my 2002 E450.