Pallet Food Display Rack Formed by 4 FSDUs

How to join 4 seperate FSDUs to form a united full pallet cardboard display? Here are steps to follow using a U shaped clip,

Brand: Subject to Bingotuzla
Model No.: PD20150613
Country of Orign: Guangdong, China
Certificate: SGS

Minimum Order: 1piece
Lead Time: 7-16 working days
Payment: T/T, Paypal, Western Union, L/C
Defaut Package: 1 piece/carton

Cardboard Display