Raemer Schreiber lowering the uranium tamper plug containing the plutonium core into the Trinity device, the “Gadget”. Note the tapered pentagonal copper funnel that sits in-place of the final polar cap to protect the High Explosive (HE) blocks from damage during the insertion, afterwards this was removed and the final HE block set in-place later to be covered by the polar cap. (Retrieved from https://preview.redd.it/6tqwx4kv5eg71.png?width=960&crop=smart&auto=webp&s=2ebd7633c661b14536556664a18958bee107cf46)