Szetech Online Archery Tools:

Target simulator
A tool to generate target faces to practice at close range whilst maintaining the sight picture and aiming angle of
longer distance rounds.

Scope ring calculator
Have the perfect scope ring/aperture/dot for a particular round? Wish you had the same at other distances?
Wish no more as with this tool you are able to calculate the exact size needed to have the same sight picture
for any distance and target face combo

Sorry for the 1999 web site look, this is only temporary and will be much imporved soon!