Hi Jim, yeah I am assuming it is custom cshells, but given this is the first I have heard of a problem with the sphere receiver failures, it could well be more of a UK problem as opposed to a worldwide one? I believe, or I should say, I have been informed, since Phonak opened their mould making lab here in the UK, probably around 18 months ago? It has been beset with all kinds of teething problems, I can vouch for that myself, having several sets of mould’s returned, and bearing no actual resemblance to what was actually ordered! So much so, I have given up trying to get Phonak to make a decent set of moulds, that fit or indeed they are not fit for purpose! Because of this, I am unable to wear my Naida Lumitys, these aids have remained redundant for approximately 4 or 5 months, and they aren’t a year old yet! Phonak make exceptionally good aids, but their mould making leaves a lot to be desired here in the UK… Prior to this, Starkey was the main subcontractor for making custom ear moulds here, and for the most part, they did an exceptionally good job…Perhaps, with the amount of returns that the Phonak mould lab is getting, they might have bought cheaper receivers to offset their losses, and this has ended up costing them much more, who knows? Mould making, is a highly skilled operation, even with 3D Printing, they have to be finished by hand, these skills take years to acquire, the slightest blemish can cause a lot of pain with a snug fitting mould! IMO, Phonak should give up the mould making, and stick to what they do best, making hearing aids! Cheers Kev 