The Aerius Quattro I 490 SL single and the Aerius Quattro II 520 double model are based on the Aerius Expedition design, but with one exceptional difference : they have 4 integrated air sponsons. This increases load capacity and maximizes buoyancy and safety. With fully inflated air sponsons, the hull shape changes from a V to a U. The latter mode allows for maximum payload and shallow water efficiency. See the difference in hull shapes in the figures below.

Military Application: The Klepper MK13 (equivalent to the civilian expedition model) was the official "stealth" kayak of NATO since 1953 and has been replaced by the four air sponson Commando known in its civilian version as the Aerius Quattro II 520 (the double version of the Quattro I 490 SL).

The Aerius Quattro I 490 SL can be sailed with the Freewind Downwind sail and the S1 sail.

Standard equipment on the Quattro I 490SL include:

black Hypalon hull with 4 air sponsons uni-coloured or two-tone Egyptian cotton deck mountain ash and baltic birch natural wood frame length adjustable seat D-ring for rudder lifting perimeter safety line deck pockets for paddles 2 x 2.4' and 1 x 10' keel strips deck bungee rear loading hatch

The rear loading hatch included on all Aerius Expedition Quattro I 490 SL Klepper folding kayaks is sealed with velcro flap and opens with a zipper as shown on this blue boat.

73 lbs / 33 kg with Hypalon hull
62 lbs / 28 kg with TPU hull

• TPU hull
• spraycover
• tarpaulin
• ground-protection mat
• rudder
• height adjustable or comfort seat
• sail

uni-coloured options:
blue
red
burgundy
olive
teal
black

two-tone options:
blue with black stripes
red with black stripes
burgundy with black stripes
olive with black stripes
teal with black stripes
teal with blue stripes