Orbea R10 El Manual Del Propietario página 8

THE PROPER FIT
Retention system: This helmet uses a retention system
that is simple and can be buckled and unbuckled
without changing the adjustment. The straps must be
snugly and evenly tensioned. Place the helmet firmly on
your head and fasten the buckle make sure you press
firmly enough to hear a "click" sound.
To tighten the rear strap, pull excess from the rear of
strap 2. Hold the helmet with one hand. With the other
hand, hold the strap where they pass under your chin.
Then pull from side to side to balance the length of all
four straps. (see Figure 4).
Fig.4
"O"ring is used for tightening the chin strap. Hold
the buckle with one hand, then pull the excess strap
through. (Figure 5)