SS42021 SS4-20-3.00-L-D-K-TR SS4-20-3.50-L-D-K-TR SS4-20-3.51-L-D-K-TR SS4-20-3.52-L-D-K-TR SS4-20-3.53-L-D-K-TR SS4-20-3.54-L-D-K-TR SS42050016 SS420C SS4216H