90 Degree Outside Joining Plate for 2020 Aluminum Extrusion

From the shop's description

These heavy duty mounting plates are perfect for any project requiring connection strength. color Black . Features 4mm Thick with M5 diameter screw holes on 20mm spacing Dimensions 60 x 60mm V-Slot aluminum bars series compatible 6105-T5 Clear Anodized Aluminum Can be mounted to V-Slot rail using 8 or 10mm screws