− | File:fiberferrulesandshrink.JPG|A 2x2 mm square waveguide, 2 ferrules, and heat-shrink used to mount the ferrules and supports to the collars. The black residue on one of the ferrules is residual RTV that is used in mounting. | + | File:fiberferrulesandshrink.JPG|A 2x2 mm square waveguide, 2 ferrules, and heat-shrink used to mount the ferrules and supports to the collars. The black residue on one of the ferrules is RTV and it is used in mounting ferrules to the collars. |