Heated handlebar inserts work with a bike’s existing grips

Nobody likes having cold hands while cycling, which is why heated handlebar grips do exist … but what if you prefer your existing fair-weather grips? Well, that’s where the Polar Plug system is designed to come in.
Invented by mountain biker Brandon Lentz, the setup consists of two cylindrical modules that are inserted into the two ends of the handlebars, in place of the existing plugs. This means that they end up almost entirely inside the bar, directly beneath the existing grips.
Each unit contains an electric heating element and a lithium battery, along with a power button on the prot