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.
| Series | Height | Depth |
|---|---|---|
| 3CF | 191 mm | 294 mm |
| 3CK | 220 mm | 220 mm |
Minimum recommended overhead clearance is 240 mm for 3CF (versus 270 mm for 3CK).
