The helix sense 300 has all the advanced functions and features of the helix sense 450 but in a lighter and smaller package with up to 300 lumens of output. These features include the unique sense mode with braking light automatic brightness sensing and parking mode. In addition the helix sense 300 also includes group ride mode to allow you to be seen on group rides without dazzling your riding friends. Specification cob red led max. Lumens 300lm fl 1 tested max.runtime70 hrs fl 1 tested battery type li po built in recharge time 230 hrs size w x d x h 22 x 19.5 x 66 mm weight 35g features 5 modes day flash steady flash flash 1 mode 1 mode 2 cnc aluminum heat sink casing sense mode brightness function motion sensing function braking function parking function lock mode auto safe mode day flash mode mode memory function variable lumen system low battery charging and fully charged indicator automatic fully charged cut off system side visibility water resistance ipx7 rechargeable lithium polymer battery usb type c charging cable