I have never been completely clear of the differences both sonically and comparability wise between the KK105 and the KK205...both wireless versions of KMS105
There are both KK105 and KK104 as well as Kk205 and KK204. Wireless capsules of the KMS105 and KMS104. The KMS105 is supercardiod while the KMS104 is cardioid.
The KK1xx are for the 5000/5200 series. The KK2xx are the same capsule for the 2000, 6000, 9000 series.
The 5000 series began in the very early 1990's so is more than 25 years old now.
As far as I know they should be sonically identical capsules although, since they cannot be interchanged between systems you can only compare entire systems to each other.
Lee