These are custom L brackets we provided our long time OEM customer. We initially had 100 pieces produced for testing and engineering inspection prior to a full commitment for 20,000 estimated annual usage. Plain low carbon steel material was used and the initial sample lot of 100 pcs was done within 1 week of print confirmation. The outside dimensions were 3/4 X 1/4 on the narrow side and 1/2 X 1/2 on the wider section, with 1/8" diameter holes drilled 1/2" from the 90 degree angle on each side.