All three leave the screen open, so pair one with a screen protector if you want glass.

Spigen Rugged Armor, Dark Gray
Series 11 / 10 · 46mm
TPU bumper with a raised lip, clearance for the crown and a carbon-fiber look. No glass included.
Check price on Amazon for Spigen Rugged Armor, Dark Gray
Ringke Air Sports Bumper, Black
Series 11 / 10 · 46mm
Low-profile, open-face TPU bumper that adds little bulk for training.
Check price on Amazon for Ringke Air Sports Bumper, Black
Ringke Fusion Bumper, Black
Series 11 / 10 · 46mm
Dual-layer PC and TPU frame built for corner knocks. Open screen and open back.
Check price on Amazon for Ringke Fusion Bumper, Black