No-Bounce design. Fits up to a 52″ chest. Made of durable 640D nylon polyester material. Easily slips over head and secures with hook and loop. Balanced weights. Includes 10 lbs of removable weights (2.5 lbs each). Includes 2 metal rings to attach resistance strap or training sled.You can add up to 10 more pounds of additional weight, for a total of 20# altogether. Additional weights sold separately (see item # BE148M).