For owners of the Tokyo Marui M870 gas shotgun series RST shows the ACE TECH M870 Dedicated Illuminator that can be mounted on these and otther compatible airsoft shotguns... "Made in Taiwan, ACE TECH m870 special illuminator is suitable for barrel diameter 23-23.5mm. (Marui M870 / M870 Breacher / A&K M870 / Golden Eagle M870) Multi-color flame (Bifrost) effect. Suitable for green and red luminous BB bombs and standard BB bombs. Highly durable aluminum alloy construction."