These snap electrodes provide the same signal transmission as the reusable electrodes, with added convenience and hygiene. Each peel-and-stick electrode is pre-gelled and designed for one use only. Use disposable snap electrodes with the LEAD110 series electrode leads. For best performance, use the LEAD110S shielded leads for your recording electrodes and the LEAD110 unshielded lead for your ground or reference electrodes. Most appropriate for long-term biopotential measurement recording sessions, these pre-gelled electrodes have a circular contact area of 1cm diameter on a 41mm diameter backing that resists moisture. The electrodes include an adhesive solid gel that adheres well to the skin but leaves no residue when removed. Quantity: 500. (Available in quantities of 50. See EL502.) EL502-10 Long-term Recording Electrodes (Pkg. 500) EL502-10$250.00 Same Day Shipping - orders with UPS Red or Blue shipping will be shipped the same day if received by 3 p.m. PT (Monday-Friday).