Lights would be my suggestions. LIGHT(S)
I would get the strongest light possible on the front as your main light and a good light that can be set to Flash as the other. And two rear lights aswell. You never see when the one rear light stops working.
And staying on lights-- That second front light could be a helmet light. Very handy if you do have to repair a flat or the bikein the dark. And a helmet light will shine where you look- so if a car looks as though it is going to casue a problem- Shine it at the driver.
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How long was I in the army? Five foot seven.
Spike Milligan