2PCS Metal Canopy Lock Washer Canopy Nut for 450 Helicopter 3MM Shaft Description: Name: Metal Canopy Lock Washer  Material: Metal For: RC 450 helicopter ( 3mm shaft  universal) Color: Silver \/ Red  Feature: Replace glass fiber canopy washer to prevent canopy hole cracking. It is suitable for 450 helicopter and common used for 3mm shaft.   Package Included: 2 x Metal Canopy lock washers