This is from the ANH Stormtrooper CRL and is a requirement for Level 3 only. I do not see the notch listed as a requirement for Sandtrooper, but you should add it anyway, in my opinion. For level three certification (if applicable): Squared cut-out sections at the lower left and right corners of the Kidney Armor. The cut out is roughly 22 mm tall from the bottom and 22 mm in from the side. Sent from my SM-N910V using Tapatalk