With the pitch as this shim is much easier to align the slots on the horizon or other motive lines. The wheel change is actually extremely simple and really only requires a steady hand and good light. The plastic box, in which the shim and the tool can be supplied, also offers a secure storage for the space Originaleinstellscheibe.
Supplement: This focusing screen is not just for the EOS 40D but also for the EOS 50D!
