K-620 fast drying, good leveling, good hardness, high brightness, leveling is good, high performance price ratio.
K-630 has a very good mirror effect, fast drying, good hardness, high brightness, leveling.
The fullness of the hardness of K-660 is better than K-630, but the dry speed is a bit slow, quick drying at low temperature can be used K-640B curing agent, but the gloss will be decreased by 1-2, the activation period of around 3H; K-660 has great advantages in price, is the main push products.
K-680 of high hardness, high fullness, yellowing resistance Xingji is good, easy to spread not easy pinholes and foaming, and K-660 in the same hardness, the difference is: K-680 fullness, brightness, yellowing resistance than K-660, but K-680 do K-660 slightly slower speed ratio