I purchased a metal 40x loupe with 2 LEDs to get more magnification than my standard magnifier.
The bad news - it seems the 40x loupe does not provide much more magnification over my supposed 20x unit,
The good news - optically it is much better and UV LED (surprise to me) is very handy at detecting phosphor and luminescence on my Machins. Since the loupe is held about 1/2 inch (12.7mm) from object to focus, the UV LED is not washed out in normal light.
The unit has some heft so if you carry it around in your pocket you will know it is there, It comes with a nice storage case a little tool to change battery.