Abstract: A mounting system for night vision tubes includes a multi-part sleeve that opens in the manner of a clamshell to receive the tube. The sleeve includes a longitudinal seam or a partial longitudinal seam and opens around compliant hinge regions. The night vision tube engages a ramp section of the sleeve, urging the sleeve to open and then abuts against a front shoulder, causing the sleeve to clamp shut around the night vision tube. The tube is constrained between the front shoulder and a retaining shoulder. An indexing pin engages the night vision tube and the sleeve to maintain mutual rotational alignment. The sleeve and the tube are inserted into a housing of a night vision system.