Roll Line - Gold 7mm Axle Locknuts ( Set of 8 ) 

Roll-Line 7mm GOLD Axle LockNuts,
Gold – Set of 8 (Brass Plated)

Roll-Line recommends changing LockNuts after about 6 times of removal or especially if you can turn them with your fingers.  When the NYLON insert wears out they will not stay in position unless locked completely down like the older style Jam Nuts.