![1girl aoki_hagane_no_arpeggio bangs blunt_bangs blush bow bowtie collar glasses greyscale hiei_(aoki_hagane_no_arpeggio) highres hitachi_magic_wand kaname_aomame monochrome partially_translated solo sweatdrop translation_request vibrator rating:s score:0 post #2825899](/cdn_image/preview/ed/89/ed89f93995dbd40e29858e91cbc485fd.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.