Few days ago we noticed that one of the two 11mm EFL collimators was behaving in a strange way. In particular the lens was not moving along X direction. I unmounted the collimator and found that the screw for X movement was broken (see picture 1 and 2).
NOTE: if you look for the collimator into the Thorlabs site the part number is PAF2P-11C. Thorlabs changed very recently the part number of this item from the one written on top of the collimator to this new one.