Are you supposed to tighten bit or does it just sit in it

This tool is designed for spiral cutting bits with either a 1/8" (3 mm), 5/32" (4 mm) (not included), or 1/4" (6 mm) shank and has a tool‑free bit change system. To change bits, FIRST turn off the tool and disconnect the battery from the tool. Remove the cutting depth guide 2 . 1. To replace bit, depress both spindle lock button 6 and collet lock 4 and turn collet grip 5 counterclockwise. 2. Insert or remove bit