YOU GET 1EA. LIONEL 249E-1 RED MARKER LIGHT WITH 2.8MM MOUNTING STEM, FOR 249E 263 LOCOMOTIVE. These can also be paired up as marker lamps for the 238, 1668,  1688, and 1689 torpedo locomotives, and other loco's with 1/8" square hole. 

WILL THEY FIT: Well I'll answer the question like this Yes they will fit, but people expect they should fit tight. They don't. they are .11 inches or just a hair under an 1/8" loco's of this age CAN BE slightly different depending on how they are stored. Unless your the original owner, we don't know if the hole has been modified, so yes they work. Mounting them I suggest 2 ways. The original Lionel way is to use a hot screw driver or soldering iron and melt the ends out larger than the hole to A fat END, on the end INSIDE of the Loco shell. My other collectors have done this and state "I have a Lionel 1668e with the original side markers and the way they are installed is to heat up the end of a flat screwdriver and flare the plastic inside the locomotive shell. I bought a pair from you for another engine and they will not fall out! "thank you Tim" or another way is by using GEL supper glue or alike thick bonding type GLUE. Really if you want a marker these are the only ones out there so kinda locks the part as the only choice, collectors buy these and we've sold over a thousand, but I get a message back saying they fall out. so I recommend DOING ONE OF THESE 2.