![1girl bags_under_eyes barefoot convenient_censoring fuwa_hyouka green_hair hitachi_magic_wand labcoat long_hair naked_labcoat necktie sanpaku shimoneta_to_iu_gainen_ga_sonzai_shinai_taikutsu_na_sekai solo spread_legs taka-tsuki rating:e score:8 post #2092775](/cdn_image/preview/ee/b9/eeb91c806f76ec8d62c07ba8168d5274.jpg)
An electric massager first released in the 1970's for medical use, it was quickly picked up and utilized as a sex toy. It looks like a strange microphone with a white and/or gray head that vibrates.
Its pixiv tag is 電マ (den-ma), an abbreviation for 電動マッサージ機 (electric massager). Not to be confused with denki anma.