The OPTI-SOLV EXP hand tight pre column filters are ideal for extreme high pressure applications. They protect columns with small particle material employing ultra high pressure techniques. The OPTI-SOLV EXP help extend and protect the life our your columns without sacrificing performance. . Titanium Hybrid Ferrule. Material: 2 ferrules and 1 nut in pack. Sold in each. . . Sigma-Aldrich 51163-U EXP Pre-Column Filter Holder with Titanium Hybrid Ferrule. Country of Origin : United States. Part Number : 1188M72EA. Pack of : 1.