M5x0.8 tap. They're cheap, they fit in a stocking, every cyclist needs one, and even cyclists otherwise well-equipped in the tool department rarely have one. Best bang for your buck for the friend you don't like enough to drop a c-note or even a twenty on, but who otherwise has everything. Also prevents friends from borrowing (and dulling or breaking) your M5x0.8 tap.
Give your friends hours of fun!
Literally hundreds of uses!
They'll think of you when they're:

• Cleaning up braze-ons after powdercoat
• Fixing messed up dropout eyelets
• Tapping some older bikes' untapped dropout eyelets
• Fixing poorly installed rivnuts
• Direct-mounting bells on stems
• And much many more!

But wait, there's more! Call now and receive not one but TWO M5x0.8 taps, plus an additional M6x1.0 tap absolutely free*

*offer valid while supplies last, offer does not include shipping and handling, MA, ME, VT, NY, RI, CT, KY, MN, CA, WA, DE, DC, PR, and other residents subject to state and local sales taxes, void where prohibited, prohibited where void, other restrictions may apply.