Are you asking this type of stuff???
https://www.amazon.com/Best-Sellers-Health-Personal-Care-Muscle-Stimulators-Accessories/zgbs/hpc/8627079011
https://www.walmart.com/ip/TENS-Unit-EMS-System-Combination-Dual-Channel-Electrotherapy-Strength-and-Recovery-System-from-iReliev/47403622?athcpid=47403622&athpgid=athenaItemPage&athcgid=null&athznid=PWVAV&athieid=v0&athstid=CS002&athguid=466001f5-911a2eb9-8b6d5ae693d53788&athena=true