go for 170 piece. very handy kit to keep in boot of car. all ratchet spanners so far better imo, and lifetime no quibble guarantee. i found the 3/8 ratchet was sticking after about 12months, took it back and it was replaced with no questions asked. i wasn't even asked for the receipt. as a tip go on halfords site and look at them and sign up for there email notifications. everything you've looked at you will be sent an email when there is a special offer on, and usually for limited time. i had my 150 piece for £79.99 and 170 for £89.99. bargain.