100% graphite ferrule; upper temperature limit 450 deg. C. Soft; graphite is recommended for use with fused silica and glass. Reusable if not overtightened. Straight ferrule is for 1/16 in. OD tubing, and fits into standard 1/16 in. Swagelok / Parker type fittings. One piece design requires no back ferrule. Packaged: 3 in. x 3 in. x 1/4 in. Plastic Dial Pack; Weight: 5.7 g