100% Vespel polyimide. Upper temperature limit 350 deg. C. 0.5 mm ID fits 0.32 mm ID capillary fused silica columns. For 1/8 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.