Named for the star, the prototype Sirius was made from wood, tube and aircraft fabric and first flew in August 1984. The prototype had an 11 m (36.1 ft) wingspan.
The production Sirius fuselage is predominately made from fibreglass, with wooden bulkheads. The 13.4 m (44.0 ft) span tapered wing has a wooden spar and Styrofoam wing ribs reinforced with fibreglass and features air brakes on the top surface for glidepath control. The wing's leading edge is fabricated from hot-wire cut foam, laminated with fibreglass. The wing and rudder are fabric covered. The fixed landing gear is a centre-line bicycle gear, with auxiliary wing tip and tail wheels. The main wheel has a drum brake. The 18 kW (24 hp) König SC 430 engine, or alternatively the 13.5 kW (18 hp) JPX D-320 engine, is mounted behind the cockpit and beneath the tail boom in pusher configuration and features a propeller guard plate just behind the main wheel. The propeller is a fixed pitch two-bladed design with small diameter. The cockpit width is 53 cm (21 in) and the best glide ratio is 23:1.
In 1998 the design was available as plans for US$220 or as a kit for US$7900. Building time from the kit was estimated as 700 hours.