My original cic aids(PHONAK 1997) were miserable because of the trial and error with the imperfectly formed shells. The most aggravating factor was a lengthy period of a sore and runny ear canal, particularly on the left. Eventually, the problem would resolve itself, but would come back after the instruments were returned from servicing. I finally decided that the problem, since it presented on the left, was due to the blue coating. The red coating apparently has a different compound which doesn’t cause an allergic response. Since then, I’ve had PHONAK silicone domes without a problem and, more recently OTICON Opn’s with domes. Then I changed to hard acrylic moulds which are not color coated. The reason for the change: I had to insert the domes so far in order to get maximum benefit that they would become detached and had to to be removed with tweezers, especially after exercise. I tried a number of different sizes, including the grip tips, which were not ideal because they aren’t made for 100db receivers. The moulds have worked out fine with no irritation, condensation, or soreness. The first pair fit properly, with only a mild increase in occlusion.