How do catchers relay signals to pitchers? How does PitchCom work

Once skeptics of pitch-call tech, Cardinals debut PitchCom after spying a strategic benefit

MLB gives OK to electronic pitch calling

No more sign stealing? Electronic pitch calling coming to big league ballparks - Federal Baseball

Will MLB use the mic'd up pitcher and catcher in the regular season? - AS USA

Dodgers deny Seth Lugo's claim they were signaling pitches - Los Angeles Times

College baseball goes high-tech to send pitch calls to mound

Thoughts on this? My son will hopefully be a freshman catcher in the spring. I'm not sure how I feel about this. “High school baseball to allow communication devices from dugout to

Rule change allows electronic communication in prep baseball – Cranberry Eagle

This is the electronic sign system the Pirates, others are using

Major League Baseball approved use of electronic device for catchers to signal pitches in effort to eliminate sign stealing - ABC13 Houston

MLB Allow Using Of PitchCom System To Combat Sign Stealing

MLB to allow anti-signal-stealing device in regular season - AS USA

MLB Signs on to In-Game Usage of Wearable Pitch-Calling Devices

PitchCom gives pitchers peace of mind signs aren't being stolen

Catcher - Wikipedia