If the orings are the same as Quad they are .158 ID and .024 thick. These dimensions are in inches. The thread for the Samsung QSA30 is 5.0 X 0.8mm, this may be the same for the CP40. If this is the correct oring size is it special and relatively hard to find. We do have them in stock for $2.00 each at Nozzle Supply Company(www.nozzlesupply.com).