Seco 1 m Aluminum Extension – 1" OD - Flo Yellow The Seco 5901-00-FLY is a durable aluminum prism pole extension designed for increasing pole height in GNSS and surveying applications. It features 5/8" x 11 male and female threading , allowing multiple extensions to be securely stacked for flexible field configurations. Key Features • Aluminum construction for lightweight durability • 1 m extension length • 1" (25 mm) outside diameter • 5/8" x 11 male/female threaded ends for stacking • High-visibility flo yellow finish