HB Body 2K High Solids Compliant Grey Primer Kit, supplied in 4L with 1L activator. A great Kit from HB Body 5:1 HS Primer Grey with 725 Hardener. .High build 2K primer with outstanding filling power for all types of paints (synthetics - single coat or base coat). It is cured with an isocyanate based BODY HARDENER (FAST - NORMAL - SLOW) @ 5:1 ratio . It can be diluted up to 30% with thinner (reducer) BODY ACRYL ( NORMAL - SLOW). Quick drying and easy to sand.