Chi-Chi's helmet
From Dragon Ball Wiki, the ''Dragon Ball'' encyclopedia
Chi-Chi's helmet is a pink helmet worn by Chi-Chi when she was a little girl. It has a detachable blade on top which can be thrown like a boomerang, which is seen when she launches an attack on Master Roshi. It also shoots lasers by using thoughts.
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Chi-Chi throwing her helmet blade
The helmet and related attacks are obvious homages to the Japanese tokusatsu series Ultraseven, the sequel series to the original Ultraman series.