San Diego Sportcycles provides helmet rental through Bruce's Auto Repair booth at each race event. They are on vendor row.
Twelve helmets are for rent so get there early. If you arrive later in the evening and need a helmet there are helmets for sale. The price range to purchase is $60 for an open face, up to $125 for a full face helmet. If you go
to their store to purchase a helmet mention RaceLegal for a discount.