Haw. Rev. Stat. § 134-8.5
(b) As used in this section:
"Bump fire stock" means a butt stock designed to be attached to a semiautomatic firearm and designed, made, or altered to increase the rate of fire achievable with such firearm by using energy from the recoil of the firearm to generate a reciprocating action that facilitates repeated activation of the trigger.
"Multiburst trigger activator" means:
(2) A manual or power-driven trigger activating device constructed and designed so that when attached to a semiautomatic firearm it simulates automatic gunfire.
"Trigger crank" means any device to be attached to a semiautomatic firearm that repeatedly activates the trigger of the firearm through the use of a lever or other part that is turned in a circular motion, but does not include any firearm initially designed and manufactured to fire through the use of a crank or lever.
[L 2018, c 157, §1]