I know this has been covered in depth in the past, but after reading all the old posts, I ended up ordering these () on eBay and installed them today.? They are very bright and the color is ice blue.? To my eyes, the result is about the same color as the original blue filters.? I left those in place as they were faded out where the light shines through.? These LED lamps are the size of the #47 bulbs and fit perfectly in the T4Xc and R4C.? Unlike my #47 bulbs, these illuminate the little XTALS window on the R4C very well.??