I really like the BD lights. I have the OnX6 in the lower center grill and just got the S2 for reverse lights. Only thing I did not love was all the silver screws in the face of the lights. So I had a bunch of Traxxas screws and tried some black button caps to see what I thought about the color before ordering enough to change all of them. Note that the black ones are button head, but I ordered socket caps like the BD OEM ones. The size is 3mm x 8mm. Here is a couple of pics.