The fixed 40 was the first of the current line up of scopes by Deon in 2007. It won everything including a world champ that year first debut out well before the first release of the 10-60 in 2008.
42 and 52 front bell available.
40, 50 and 60mag fixed weigh in at 590Gr lighter than a Comp Series, 10-60 730Gr.
Generally the 10-60 is a variable mag fixed 60 mag BR around £300 extra and 140Gr heavier.