 The Mod 0 to 10 versions of the B61 are equipped with a parachute retarder (currently a 24-ft (7.3 m) diameter nylon/Kevlar chute) to slow the weapon in its descent.This offers the aircraft a chance to escape the blast in its retarded modes, or allows the weapon to survive impact with the ground in laydown mode.The Mod 11 is the newest variant.