Don't know why, perhaps due to rising demand and production bandwidth, but be forewarned quality control is an issue. Assembly is easy enough, though have gap where back separator does not fit snugly after tightening nuts as firm as they will go (see pic). No water level sticker on tank received, so had to measure water manually according to calculations (4 gallons). Siphon was not air tight (even though release valve closed firmly), so had to manually pump instead of siphon. S4 monitor only flashes, not working as of yet and now have to take a apart top of unit to figure out why, currently not resolved after verifying connections and looking at simple solutions on website.

There are 4 main rowing machine types that are classed according to its utilized resistance mechanism. Having an exercise workout needs to have resistance against the movement in order to provide to the muscles and the cardiovascular system a good change. This can be provided by the rowing machine whenever you pull its handle and then slide back to the seat. Having low resistance works on the cardiovascular system can make you row fast easily. Having high resistance means that it provides you with the anaerobic session, working with the muscles harder, also having a slow stroke rate because of the harder pull.
The WaterRower Xeno Müller Signature Edition rowing machine is handcrafted in solid ash and finished with honey oak stain for color. The WaterRower Xeno Müller Signature Edition has been specifically designed in collaboration with US Olympian and single scull record holder Xeno Müller. This special edition rower features a wider 17" handle and lower footrests for an increased range. Another special feature is Xeno\'s signature included on the rails of either side of the rower thus inspiring you to row like an Olympian!
 The amount of water in the tank simulates the weight of the boat and crew, the more water in the tank the heavier the boat and crew. The standard Calibration Level is Level 17. If the user is lighter in weight, Level 15-16 can be used. If the user is heavier in weight, level 18-19 can be used. The maximum level to fill the tank is Level 19. DO NOT fill above the maximum level – this could void the warranty.
The water flywheel is comprised of two paddles encased in an enclosed tank of water. As you pull the cable, the paddles move through the water creating resistance. The beauty of this machine is it uses the mass/density of water. The paddles create the drag, so the harder you pull, the more resistance increases. Think about moving your hands through water. The faster you go, the more dense water feels. The slower you go, the less you feel the resistance. And this type of resistance is excellent for your joints. Click here to read the full review.
The main advantages of the water rower are that it has quiet operation; there is only little maintenance to do, the water only needs to be changed occasionally; many users love the whooshing sound of water in the tank; and its consistently smooth resistance at every stroke. Two disadvantages of this machine are it costs a lot than the air rower; and it tends to be larger in size compared to the other rowing machines.
Other details include dual rails with four corner wheels that increase seat stability and reduce the amount of sweat buildup; a frame that flips upright for handy storage; and a weight capacity of up to 1,000 pounds. The WaterRower Natural measures 84 by 21 by 22 inches (W x H x D), weighs 117 pounds (with water), and carries a one-year warranty on the frame and components (WaterRower will upgrade the warranty to five years on the frame and three years on the components with the completion of a registration form).