Hellermanntyton high shrink ratio heavy duty heat shrinkable tubing ha67 hellermann tyton 321 30000 the hellermanntyton 321 30000 is a high shrink ratio heavy duty heat shrinkable tubing from the ha67 range this 61 ratio heat shrink has been designed to pass over large size connectors and shrink down onto much smaller cable jackets the thermoplastic adhesive lined tubing provides environmental sealing excellent insulation and resistance to impact and abrasion the 61 shrink ratio confor