SMS marketing question

Does anyone use SMS marketing through the Redbox system. I’m interested to hear your thoughts. I was just looking at it to test it out. I thought 160 would be the character limit as this is a standard text message limit but it seems to cut off at 77. This is a text only message with no emojis however it does have commas ect.

My next question is, what kind of messages can we send with a 77 character limit?