Hi Jan,
I contacted Kowa some time ago about availability of eyepieces for the Kowa TSN-1/2/3/4 series; here is the reply I received:
> Thank you for your e-mail. All of the eyepieces for the current > TSN-600 and TSN-660 series are compatible with the TSN-1/2/3/4 > scopes. The current lineup of these eyepieces are as follows: > > TSE-Z9B 20-60x Zoom > TE-9WD 50x Wide Angle > TSE-14WD 30x Wide Angle > TSE-17HD 25x Long Eye Relief
