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.
The helmet and related attacks are obvious homages to the Japanese tokusatsu series Ultraseven, the sequel series to the original Ultraman series.