Shaft Height: Approx. 18'' Tall. Reengineering our proven work boot comfort system, we've taken Quad Core technology and redesigned it specifically for hunting boots. For the first time ever, our Quad Core 4-layer comfort platform system has been integrated into the 4xBurly that features uncompromising scent free and waterproof protection, now with uncompromising underfoot comfort and support. Adjustable back gusset and strap with adjustable fit for various leg sizes, added rubber abrasion protection in toe, heel and shin.