SPL + 3.
Matk + 5 and S.Matk + 3 per 20 base SPL of the user.
If the enchanted equipment is grade D, additional S.Matk + 1 per 20 base SPL.
If the enchanted equipment is grade C, additional S.Matk + 2 per 20 base SPL.
If the enchanted equipment is grade B, additional S.Matk + 2 per 20 base SPL.
If the enchanted equipment is grade A, additional S.Matk + 2 per 20 base SPL.