This is a single NOS power window switch (plastic) for quite a few GM applications from 1978 forward. Here is the list for switch part number 20043940:
1978 - 1979 Olds Buick and Chevrolet 4 door A-Body with rear power vent windows.
1979 GM A G body 2 and 4 door left door switch, and right rear on 4 door applications. Monte Carlo El Camino regal cutlass Malibu Grand Prix
1981 - 1991 Chevrolet GMC trucks C/K R/V Blazer Jimmy Suburban Silverado Sierra Classic
1982 - 1985 Chevrolet GMC S10 S15
1979 Cadillac Deville Fleetwood power sunroof switch
1979 - 1980 Cutlass 98 and Toronado power sunroof switch
1981 - 1996 Chevrolet GMC G-Series Van g10 g20 g30 g1500 g2500 g3500
I found an extended list on a dealership website that extends applications to additional 1982+ applications but I cannot verify that via my OG paper dealership books and part number history books.
Brand new in original box.
80 82 1983 83 1984 84 85 1986 86 1987 1988 1990 90 1992 92 1993 93 1994 94 1995 95 96 c10 c20 c30 c2500 c3500 c1500 k10 k20 k30 k1500 k2500 k3500 crew cab regal grand national caballero.
All packing/shipping/moving of parts is done on weekends. Ebay is not my full time job and my storage is an hour round trip from my house, so moving parts around on weekdays is not in the cards. If you need something immediately, I'm not your guy. The handling time is built into my delivery estimate on auto parts. All large items are packaged by a shipping company, and go out on Monday or Tuesday depending on how busy they are. I package all smaller items and drop off for Monday pick up.