Aluminum Spacer Black 3/4" OD x 3/8" ID x Many Lengths Round by Metal Spacers Online (1/2" Length, 10)
Brand: MetalSpacersOnline.com

All aluminum spacers are tumbled and have an black anodized finish

Outside diameter: 3/4"/19.05mm
Inside diameter: 3/16"/4.76mm (fits #10 or M4 bolts)
Length: Varies-Choose Length
Shape: Round
Material Type: T-6061 Aluminum with black anodized finish