It is a 1974 Bell start helmet used by Ayrton Senna during the 1975 kart season with dark green visor.
It has been hand signed on the crown by Ayrton Senna, there is also a label inside left chin with the inscription " A DA SILVA"
The helmet bares the Brazilian FIA logo ( Automovel Club Do Brasil)
It has also been signed by Sid Mosca at the back .
The 1975 season brought important go-kart titles to Ayrton Senna: he won two editions of the Canovas Tournament, the Go-Kart 50 Miles, a Summer Tournament and the Itacolomy National Tournament, the Brazilian Runner-Up – Youth Category, the São Paulo Champion – 100cc Category