MasterSeal® M 200 (Formerly Sonoguard Base Coat) is a polyurethane membrane waterproofer used in conjunction with MasterSeal® Topcoats for use either interior or exterior. It is a liquid applied moisture-cure polyurethane seamless waterproofing membrane. As part of the MasterSeal Traffic 1500MD system creates a tough, continuously elastomeric properties achieve long term protection against water ingress. High skid resistance with aliphatic top coat ensures long life and suitability for public locations.