The classic, old-timey type metal diving helmet based on a few images from videogames, comics and photos.
Haven't seen any LoRAs for this type of helmet, since modern ones are more likely to surface. Like many LoRAs I train, the focus is just the headgear.
trigger word is either "retro_divehelmet" or "diving helmet", should respond to color prompts I think. You might end up prompting the helmet from Disney Dreamlight Valley since that was part of the dataset.