Easy off ZipSider Styling with protected zip for easier use. Heat resistant to 300 degrees C. PU Midsole with scuff cap. Fully lined steel toe-cap OrthoTec PU innersole The 561050 'High Ankle ZipSider Boot’ from Mongrel is from the SP ZipSider Series. Originally designed to meet the needs of tradesmen requiring a boot that was easy to slip on and off but provided greater ankle support - increasingly required on many worksites. The SP ZipSider range has been redesigned and new styles included as a result of demands in specific industries,including construction. ZipSider styles feature the OrthoTec PU Innersole.