A large Rogowski coil with a color (orange) and size similar to a hula hoop.
https://cybre.ams3.digitaloceanspaces.com/media_attachments/files/108/871/187/790/156/892/original/0e4c94c010e4a854.png
Rogowski hula hoop - get some exercise when you're not measuring 1000 amps.
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.