This is the plastic battery tray that sits in between your battery and steel battery tray. This is a genuine OEM Honda part.
Honda Parts:
1X 31521-SR3-000
1X 31512-SR3-000
2X 31513-SR3-000
2X M6 Flange Nuts - Yellow Zinc
OEM Honda Acura Battery Tray & Bracket Set
SKU: 006C-B00-00497
$59.99Price
