Check out this great training aid from Avantiplus Blenheim. Functions include: Current Speed, Maximum speed, Odometer, trip distance, clock. Ideal for kids, mum and dad cyclist. Fits any size bike.  There will be a voucher from Avantiplus Blenheim in every goodie bag for the kids when they cross the finish line to buy this speedo at half price – was $40 now only $20 with voucher.