Ryobi CH485K 450K 460PK. THESE DO NOT FIT THE CHEAP CHINESE CONCRETE BREAKERS LIKE YOU BUY FROM SCREWFIX AND B&Q ETC THERE ARE 30MM HEX . Kango fitting breaker steels. IF THEY DO NOT FIT. ASK IF YOUR MACHINE IS NOT LISTED BELOW AND I WILL LOOK INTO IT TO SEE IF THEY FIT THAT MACHINE YOU ARE ASKING ABOUT.