Material: Plastic Lengths: 7.5/13.5/19.5cm For use, you can take them separately to mount any length you want (we have 3 for choice.) or connect each other as 2 or 3-fold stick. We do not recommend that you use it as 2 or 3-fold stick for speed sport , please just use one of them. Perfect Bow for Self-Firing - Helmet Sight; This set of arch extension arms contain 3 lengths for self shooting images. It's designed to work with helmet mounts, so you'll always get the best footage. Compatible replacement for GoPro accessories, not original. Works with GoPro mounts and accessories, designed to securely attach to other action camera mounts and accessories. Suitable for 180 degree auto photo shooting as a camera mount for the motorcyclist , sprinter and cyclist. Material: Plastic, Lengths: 7.5/13.5/19.5cm; 3-in-1 arc arch extension arm kit ideal for taking continuous POV shots and motion cam selfies For use, you can take them separately to mount any length you want (we have 3 for choice.) or connect each other as 2 or 3-folding stick