Yep welcome Herman. That SIB (as we'd call it not having a GRP outer hull) is unusual but Google found me loads of images and web pages where it is mentioned but not always in English.
Image...
http://www.boat.no/sevylor/sevymarine-sv10-3.JPG
It's on the page marked 416 (oddly it starts at page 412) of this electronic brochure...
Luftmatratzen von KK Kunz und Hages
Spec I've translated from a data sheet...
Sevymarine SV10 inflatable boat , manufactured by Zodiac in France. CE- category C ( up to 6 Beaufort wind and waves up to 2 m ).
Floor boards are wooden and alloy. Two main air chambers plus keel.
Length 3.05 m, width 1.5 m
4 adults
Outboard 10hp maximum
Specially reinforced polyester material (not PVC)