You can find them here:
http://www.maximum-velocity.com/pinewoo ... .htm#micro
Each package contains one ounce of weight (17 cylinders). Each micro-cylinder measures:
0.209 OD (just under 13/64)
0.185 long (just under 3/16)
1.7 grams each
0.040 through hole (most of these are plugged up)
Micro Tungsten Cylinders are typically used as trim weighting for cars. They can be inserted individually into holes (drill 13/64), or can put poured into a larger hole or cavity. Secure with epoxy or hot glue.