More information about the S1 mini Lifer Helmet:
The S1 mini Lifer Helmet has a smaller shell than the S1 Lifer Helmet.
The S1 mini Lifer helmet fits head sizes between 18.5" - 20.5". Generally speaking this helmet will fit boys and girls under 11 and petite adult women.
For example, the XS will fit your 3 year old beginner perfectly! The S1 mini Lifer is designed to fit nice and low on the head so you get full coverage.
The S1 mini Lifer Helmet replaced the S1 Kid Helmet.
Interesting Information: if you see an S1 Helmet with a red clip... it is a mini Lifer Helmet.