Thule Yepp Maxi Bicycle Child Seat The Yepp Maxi is suitable for carrying children up to a maximum of 18kg/ 40 pounds including child, pack and contents. The seat can be attached to bicycles with a frame size of 21 inches or larger and a seat tube diameter of 1.1-1.8 inches (28-45 mm). Dutch Design meets Safety: Meets stringent European safety requirements and ASTM standards. 5-point safety harness with user-friendly buckle and easily adjustable footrests with straps provide optimal protection.The Yepp Maxi is suitable for carrying children up to a maximum of 18kg/ 40 pounds including child. All Yepp child bicycle seats are made of flexible rubber foam which is very comfortable and shock absorbing. It has a high insulation factor (summer and winter) and no watter penetration thanks to closed cell-structure. Safe, Easy to Use, Comfort, Award Winning Design. Quick and simple to snap into place and detach, lightweight, anti,bactirial and easy to clean. Easily secured with anti,theft lock. Use the Yepp products only on a bicycle that is in good working order and of the type suitable for carrying the additional load. Contact the bicycle manufacturer to obtain this information.