This a Number 8 left hand stub turnout, frog angle 7 degrees 9 minutes.
Once installed you will find it as Turnout Stub 8L in the Fixed track menu.
You can switch which side the lever is on as well as the starting track direction in the Surveyor properties window.
Thanks to Bob Pearson and andi06 for the scripting assistance!
Revision 2: increased sensitivity of roll to match slight grades better
Revision 3: Optimised script slightly