Very short reducer 2 "i to T-2a, only 1.5mm optical length Converts a 2" (50.8mm) external thread into a T-2 (M42x0.75) external thread Allows shortest possible, tight-fitting T-2 adaptation to SC thread, if necessary with additional TQC / TCR heavy duty T-2 quick release system #2456322 For a rotatable SC/T-2 connection, we recommend our rotatable SC / HD to T-2 adapter, ultra short, 9mm length #2958500B with 7mm optical length Is required, for example, to be able to attach T-2 components to the output side of the Research Grade TZ-3 telecentric system (this ring is already included in the TZ-3 scope of delivery)