661 evo am mips helmet661 has chosen the best fit system on the planet for the evo am mips helmet the boa fs360 allows you to get a custom fit every time in place of standard eps foam liners 661 has substituted it with contego eps foam contego foam is superior to eps foam with far greater impact absorption featuresin moulded construction with 15 oversized ventsmips multi directional impact protection system integrationmade with contego eps an eps that can substantially reduce impact micro