These are the kits you can ride on UK roads and cycle paths without registration, tax or insurance. To count as an EAPC in Great Britain a converted bike needs working pedals, a motor rated at no more than 250W continuous and assistance that stops at 15.5 mph (25 km/h); the rider must be 14 or over. All three kits here meet that: 36V or 48V 250W front hub motors with the assist limit set in the controller.
Power above 250W is not road legal, however the controller is set, which is why our 500W and higher kits are sold for private land. Our UK legal conversion kit guide explains the rules in plain English, with the government source linked.
Choosing between them: the EZ Rider comes with two batteries and fits Brompton and standard bikes; the 36V/48V 250W kit is the complete-kit option with a bigger battery; the 250W motor wheel is for riders who already have a battery. Check fit with the wheel and dropout guide.