I purchased the Walkvest about 6 months ago. It is a vest that slips over your clothing and clasps shut. There are small pockets all the way around it that hold .5 lb weights (included). It comes with two pounds of weights but more can be added and it holds a maximum of four pounds. You insert the desired amount of weight in the pockets and off you go for your walk. It is super confortable (even in the dead of summer) and to date, I've lost 18 lbs simply by wearing this when I walk. I has reflective strips on it so drivers can see you (although I have not used it at night). This is a fantastic product...it was even featured on Oprah!