This construction is very often used for public swimming pools because the automatic shutter completely closes off the cover pit. The roller system should, if possible, be positioned on the skimmer side so that, in the case of an outdoor pool, the coarse contamination is transported directly in front of the skimmer.
| Construction: | The roller system is mounted below the bottom of the pool with an automatic shutter |
| Installation: | Only for new pools |
| Maximum size: | 25 m x 50 m (larger sizes depending on pool shape) |
| Drive unit in separate motor pit: | Drive unit mounted on the shaft, or chain drive |
| Drive unit without motor pit: | not possible |
| Cover slats: | Standard slats 60 mm wide and 14 mm thick |
| Guidelines: | Installation approved for private and public swimming pools |