From the manufacturer

Don’t let a broken tent pole interrupt your trip. These tent pole splints let you repair a pole on the fly so you can stay in the backcountry. Available in two sizes, the Small (13 mm / 0.51 in) repair sleeve fits 1-, 2-, and 3-person MSR tent poles, while the Large (16 mm / 0.63 in) splint fits 4- to 6-person MSR tent poles.