Use wet or dry for sanding old finishes, fine featheredging plus surface work. It is a silicon carbide, closed coat product bonded with a waterproof resin.

Abrasive Backing Type: Paper
Abrasive Backing Weight: A Weight
Abrasive Mineral Type: Silicon Carbide
ANSI Grade: 400
Color: Black
Length: 11 Inch
Width: 9 Inch