The AV110 was developed fot the use of auto focus lenses in the U-A series of ewa-marine housings. The function of the AV110 is to ensure afixed and rigid connection of the housing's front port to the tripod threadunder the camera's body. This then allows the autofocus to lengthen or shortenthe effective length of the lens without beeing effected by the surroundingwater. Without the AV110 the lense's motor would have to "pump" air from therear of the housing to the front, and vis versa, during focussing. Thisdefenitely exceeds the design specification of the motor and could lead todamages of the lenses mechanics.
Naturally, the AV110 can also be used in all the currenthousings of the U-F... series.
The AV110 was developed from the predecesor, the AV100.Housings that were designed for the AV100 can also use the AV110. Olderhousings, that were supplied with the AV90 can not use the AV110!
as supplied in the U-A and U-AX (System length: camera/lens max. 170 mm)