Yes, there is a GLE-S and GL4-S. I have the GL4-S in the truck waiting for me to install my ATT. I asked what was different without going into specifics. He used an analogy about colonel Sanders and his 11 secret herbs and spices and told me he couldn't divulge his secrets either. He is a super nice guy to talk to, I just wish I could have learned more about what I was buying.