Corteco shaft seals are among the best on the market. We therefore recommend them without reservation for all engines and power ratings. Sets which are marked with -CORTECO- contain only shaft seals from Corteco.
They are available in different materials:

CORTECO BLUE (NBR)
The blue Corteco shaft seals are made of NBR rubber (acrylonitrile-butadiene rubber). Compared to the standard material (usually black), this has a higher wear resistance. Temperature resistant up to approx. 100°C.
CORTECO BROWN (FKM/FPM)
The brown shaft sealing rings are made of FKM/FPM (fluoro rubber). They are highly resistant to abrasion with low friction and very high resistance to ageing. They also have a temperature resistance of up to 200°C. They are therefore mainly used in the crankcase area. Our first choice for all performance-enhanced engines.
The shaft seal sets for the Vespa PX, Cosa and T5 engines differ fundamentally in two things:
material large crankshaft seal ring
rubber
metal
dimensions rear wheel shaft seal ring
PX old (-1984): 27x47x6mm
(mounted from outside, for brake drum with Ø27mm flange)
PX Lusso (1984-1989): 30x47x6mm
(mounted from outside, for brake drum with Ø30mm flange)
PX Lusso (1989-), My, Disc, 2011 etc. : 27x42x10mm
(mounted from the inside, for brake drum without oil seal surface. Flange = Ø31,5mm, is used with felt ring)