18033-M16-IK External M16-Ikelite Optical TTL-Converter for SONY A1-A9II family cameras for IKELITE underwater housings

External M16-Ikelite Optical TTL-Converter for SONY A1-A9II family cameras for IKELITE underwater housings.                                          Installation in M16 threaded hole on the top of the housing + nut.  Compatible underwater strobes: Inon S-220 / Z-330 / Z-240, Sea&Sea YS-D1 / YS-D3 Mark II/ YS-D3 Mark II/ YS-D3 DUO, Retra Pro MAX (including HSS),  Marelux APOLLO III V2.0 (including HSS), Marelux APOLLO-S (including HSS).