hi mate, yes im a builder by trade. you can pick up the ones that you put into a cordless drill up really cheap in cov. you get them in the pound shop, im sure there is one near you somewhere. they might not be dewalt ,but iv had mine 3 years and its used most days. brilliant for a quid mate. they are orange in colour and some are blue in colour. get down to the pound shop mate. all the best.