so far in my research
http://www.extremeglow.com/store/p/27-F ... -Pack.aspx
i removed the mirror paper and bent it like in the picture now is 3/4" x 7/8" x more or less 2/5 thick

anyone has used anything smaller
in the same place they sell the (1/2" round x1/2" thick)
http://www.extremeglow.com/store/p/32-B ... ights.aspx
unfortunately they only blink i need steady light