The “E” Bosch coils are normal ones.
The “K” Bosch coils are high efficiency.

TJ6/1 Motorcycle coil
Bosch part number
DKW part number “8801 310 7000”
Prüfrex DIN 75231

TE6/3
Bosch part number

TK6/3 (Black) fat star refers to the bottom
Diameter 63.8 mm
Bosch part number

TK6/4 (Blue) fat star refers to the bottom
Diameter 63.8 mm
Bosch part number

TE6A3 (Black) start 01-11-1950
Diameter 55 mm
Volkswagen part number original 917021A renumbered to 111905105C
Bosch part number
Volkswagen Spark plug Bosch W175T1

TK6A3 (Black)
Porsche part number “616 602 108 00” / “547 602 101 00”
Volkswagen part number 111905105D
Bosch part number “0 221 100 016” / “0 221 101 016”
Prüfrex PX 6/102
Volkswagen Spark plug Bosch W145T1 / W175T1
Porsche Spark plug Bosch W225T1 / W240T1

TK6A4 (Blue)
Diameter 60 mm
Bosch part number “0 221 101 001” / “0 221 116 001”
Prüfrex PX 6/102
Porsche Spark plug Bosch W225T1 / W240T1

TK6A11
Bosch part number “0 221 101 003”
Prüfrex PX 6/102

TK6A15
Bosch part number “0 221 101 010”
Prüfrex PX 6/102

TL6/1
Diameter 52.2 mm
Bosch part number

TE6B1 (Black) start 14-08-1956
Volkswagen partnumber 111905105D
Bosch part number

TE6B3
Volkswagen partnumber
Bosch part number
Volkswagen Spark plug Bosch W175T1

TE6B4 (Black)
Bosch part number

TH12/1
Bosch part number

TK12/3
Bosch part number

TK12A3 (Black)
Bosch part number

TK12A4 (Blue)
Bosch part number “0 221 102 003”

TK12A9 (Black)
Bosch part number

TK12A10 (Black)
Bosch part number

TK12A11 (Blue)
Bosch part number

E6V
Volkswagen partnumber 111905105K / 111905105M / 311905105
Bosch part number “0 221 100 012” / “0 221 100 014” / “0 221 100 025”

E12V (Black)
Volkswagen partnumber 043905115A / 113905115C
Bosch part number “0 221 114 014” / “0 221 143 007”

K6V (Blue)
Volkswagen partnumber
Bosch part number “0 221 101 003” / “0 221 101 005” / “0 221 124 001”

K12V
Volkswagen partnumber
Bosch part number “0 221 102 003” / “0 221 119 027”

KW12V
Bosch part number “0 221 102 042”