Disposable hydrogel ring electrodes by The Electrode Store. 0.3" x 4" (8mm x 100mm) strips with superior Ag/AgCl adhesive conductive material 3 times as thick as most disposable electrodes for improved sticking and recording. Requires reusable alligator clips. 2 year shelf life. (Pack of 100). Please note: This item is in limited supply until we receive more - expected to be in mid-December.