Carver risers are made of soft rubber to absorb shock and help increase the truck height to prevent wheel bite.
One single back and front riser. Please note the C7 riser uses a longer riser for the front to match C7 truck baseplates.
The size is 3/16” (4.78mm) which is slightly higher than 1/8” (3.18mm) but smaller than 1/4” (6.35mm)