100% full grain leather cover is super strong and durable to provide maximum longevity and top results. Inside 2" poly rubber liner provides an ideal striking surface and increased hand protection. Specially blended poly-fiber filler is professionally packed to provide resilient shock absorbency and maintain a firm, cylindrical shape for life. Center aligned weight is precision placed for maximum force dispersion and balance. Includes four triple reinforced hanging D-rings on top with durable seat belt nylon hanging straps to alleviate chains and excess noise. Includes a tie-down D-ring on the bottom for securing the bag to the floor, if desired. This is the heavy bag that has outfitted professional gyms and institutions for more than a decade. Swivel sold separately.