[['colt model no', 'name', 'stock', 'fire control', 'rear sight', 'forward assist', 'barrel length', 'barrel profile', 'barrel twist', 'hand guards', 'bayonet lug', 'muzzle device'], ['le1020', 'gas piston carbine', '4th generation', 's - 1', 'flattop', 'yes', '16 in', 'm4', '1:7', 'rail system', 'yes', 'a2'], ['le1033', 'gas piston commando', '4th generation', 's - 1', 'flattop', 'yes', '11.5 in', 'a2', '1:7', 'rail system', 'yes', 'a2'], ['le6920hb', 'law enforcement carbine', '4th generation', 's - 1', 'flattop', 'yes', '16 in', 'm4 hbar', '1:7', 'm4', 'yes', 'a2'], ['le6921', 'm4le carbine', '4th generation', 's - 1', 'flattop', 'yes', '14.5 in', 'm4', '1:7', 'm4', 'yes', 'a2'], ['le6921cqb', 'm4le carbine', '4th generation', 's - 1', 'flattop', 'yes', '10.5 in', 'm4 hbar', '1:7', 'm4', 'yes', 'a2'], ['le6921hb', 'm4le carbine', '4th generation', 's - 1', 'flattop', 'yes', '14.5 in', 'm4 hbar', '1:7', 'm4', 'yes', 'a2'], ['le6921sp', 'm4le carbine', '4th generation', 's - 1', 'flattop', 'yes', '10 in', 'm4 hbar', '1:7', 'm4', 'yes', 'a2'], ['le6933', 'm4le commando', '4th generation', 's - 1', 'flattop', 'yes', '11.5 in', 'a2', '1:7', 'short ribbed', 'yes', 'a2']]
all Ar - 15 Variant use Flattop as a Rear Sight
all [ENT] use [ENT] as a [ENT]