No I don't. I grabbed the 4 colors of tubes I had and taped them together side by side (oooo) w/ black tape so I could also make them all the same effective length and handed them to my wife. Said hold them up so you see just the ends and tell me which is brightest to you. BTW maybe it's just the Dawsons we have bought for Beretta 92s, but they use .040" tubes. The other common size tubes is .060". So I carefully drill the sight to 1/16" (.062") and then use the larger tubes for an even brighter dot.