Mouthgard- Is this normal?

[cpcompany]

Just picked up my new mouthguard from my dentist but I am slightly concerned.The mouthguard itself fits perfectly and I barely notice it in my mouth. But, its incredibly thin and the material is fairly soft. I am a bit worried about any damage to my teeth when i get a hard smack in the mouth.
The mouth guard is nowhere near as thick as the shockdoctor I had, and seems to offer less protection for my teeth. Are they supposed to be this thin?