Park Tool CT-5 "Mini Brute" Chain Tool

This small chain tool goes anywhere and actually
performs like a shop quality tool. The fine thread, special
"V"-shaped handle, and super strong replaceable pin
make chain removal and installation a breeze. The CT-5
works on any derailer chain (including Hyperglide®) and
has a "shelf" for loosening tight links. At only 77 grams,
it1s the perfect take-along chain tool. Works great on 9
speed chains as well.