well i bought one..its great for school use (since its summer i dont use it much..) or if your going on a road trip and you wanna keep finger strength up....but yeah use it for your pinky and challenge your fingers they do get stronger. worked for me.

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Seems a bit ridiculous to me. You don't need strong fingers to play guitar. Anything you lost when you haven't played for an extended time you get back in a few days to a week of actually playing guitar.
Things with strings:
Ibanez J.Custom, Prestiges, RG8, SR5 bass etc
LP's, Strat, Tele
ENGL Retro Tube 50
5150 III 50W
Orange Terror Bass
Your looking for dexterity and endurance. I would spend that time stretching wrists/fingers, and do actually.

While your at it, stretch your legs as well. There is a reason cats are so damned happy.
"If you're looking for me,
you better check under the sea,
because that's where you'll find me..."
Unless youre going 2-3 weeks between playing guitar. Dont waste your money on that shit.
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