HEUER/GÜBELIN Autavia reference 2446 very rare intermediate wheel chronograph, manual winding, Switzerland around 1968, stainless steel case, screwed down case back with no. C 878-2, case-no. 89111, rare revolving tachymeter-bezel, black dial with silvered luminous indexes, silvered sub-dials, original hands, rhodium plated movement calibre Valjoux 72, 17 jewels, glucydur-screw balance, movement, case & dial signed, diameter approx. 39 mm, condition 2, collectable