Available in zinc or in corrosion- resisting steel. Examples: AN100-3(carbon steel), AN100-C3(stainless steel). Thimbles are made in conformance with Government procurement specification MIL-T-5677 and standard drawing AN100.
Heard about Boelube for years. Finally had a chance to try it on several projects. It definitely works well and better than anything else I have ever tried. Would recommend.