There ought to be a great aftermarket selection, albeit custom. I've not seen horizontal carry for a multitool yet, but it seems it would work. I had considered making such a beast a time or two, but haven't found the need to be assertive enough as yet.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)