60% Vespel / 40% Graphite ferrules have an upper temperature limit of 400 deg. C. 1/4 in. ID is for 1/4 in. OD tubing; ferrule fits into standard 1/4 in. Swagelok / Parker type fittings. One piece design requires no back ferrule. Packaged: 2-3/8 in. x 1-1/4 in. x 1/2 in. Plastic Hinged Box; Weight: 8.5 g.