The Petzl Grigri belay device is one of the most popular belay devices on the market. In the following videos you will find out in detail
Petzl Grigri
GriGri 2 – Zip-Gear
Self-lowering - Petzl USA
News - Petzl GRIGRI+: OPTIONS TO ENSURE A GREAT BELAY - Petzl Other
How To Belay with a GriGri - Learn To Rock Climb - VDiff
How to Give a Perfect Lead Belay with a Grigri
How to belay with the Petzl GriGri
How To Use A Petzl GriGri + NEW GriGri+
How to properly belay with the Grigri 2 and Grigri+ from Petzl - Lacrux climbing magazine