D'Addario Guitar Tuner - Micro Headstock Tuner - Tuner for Acoustic Guitar, Electric Guitar, Bass Guitar, Mandolin, Banjo, Ukulele - Compact & Discrete - Clip On - 1 Pack

Keep one of these clipped to your most used/gigging bass. Then no matter what, you always have a backup. 3 of my basses have them on and I forget they’re there until I need them. D'Addario Guitar Tuner - Micro... https://www.amazon.com/dp/B005FKF1PY?ref=ppx_pop_mob_ap_share