3CF and 3CK series offer the same performance, construction, and lengths. The main differences are in their cross-section dimension (see table below). 3CF is more suitable when there is limited clearance between the top of the door and ceiling.
|3CF||191 mm||294 mm|
|3CK||220 mm||220 mm|
Minimum recommended overhead clearance is 240 mm for 3CF (versus 270 mm for 3CK).