Don't believe CQR ever made a 55 so my bet is a 45. The next size up is a 60. If it's a 45 the Manson at the same weight is probably a better anchor but of course bigger is better. If it's a 60 just keep it and use it. I have been using my 60lb CQR for 11 years and it's been fine. Dragged once where nothing would have held, sand over rock... I picked a bad place. couple of other times had to work to set but no big deal. FWIW boat is 47 and about 32000 lbs. Oh and as held through storm of 50-60 knots.