This OKO carburetor kit is for SWM 240s and 280s and other brands using the same Rotax motor, like Aprilia.  The 240 engine uses and 26mm and the 280 (also known as the 320) uses a 28mm or 30mm (both have the same bottom end, but the 30 has more top end), so just let us know which you have. They are available in black or metallic.  We are a direct buyer from the OKO factory in Taiwan and do not sell the cheap Chinese copies flooding the market.  You can tell the genuine by the Taiwan flag on the box, which the Chinese do not use (or they cover it, see above photo).  As trials riders/tuners, we have installed several of these kits on these Rotax engines with very good results, increasing low and mid-range power significantly over the stock DeLorto carburetor.  Each carburetor is disassembled, inspected, rejetted, has the float level checked and has the pilot and main circuits checked.  We also include extra jets for fine tuning, since airboxes and exhausts sometimes differ.  We offer a 90 day warranty as well as a 30 day return policy if you are not satisfied for any reason.  This carb. is a direct fit into the stock manifold and the kit includes a rubber sleeve for your air box sleeve for a good fit over the intake.  Feel free to contact us with any questions.