Caps heat-shrink intended are for securing line po earlier cleaning. eliminate possibility re contamination line, which is problematic and has space in traditional methods (badly matched plastic plugs czy caps inserted or screwed-in for ends can leave particles resulting through shearing material thread). caps heat-shrink not leave po itself no contaminants. until are on ends cleaned previously line we have guarantee, that is on still clean. removal such caps consists in on pulling black stripe (placed along caps) in direction fittings line. caps are single-use use and re ich use is impossible.