A - Plated - through holes. At least 4 plated-through holes shall be present on the sample.** The plated-through hole sample location is optional, but shall not contact other circuit pattern features. B - Maximum diameter unpierced circular conductor specified by fabricator. C - Distance from edge of circular conductor (B) to edge of sample shall be sufficient to accommodate plated through holes (A). ** - Optional, but MUST be on samples if acceptance of this type of construction is desired.