Trimble GEDO Extension for Prism in Frame, 30 cm Extend the working height of a Trimble GEDO Prism in Frame with this 30 cm stainless steel extension . Designed for track surveying and other precision prism applications, it uses a standard 5/8" threaded connection for secure attachment to the compatible prism frame. Key Features 30 cm (300 mm) extension for increasing prism setup height. 5/8" threaded connection for compatible Trimble GEDO prism equipment. Durable stainless steel construction for demanding field use. Genuine Trimble GEDO accessory designed for the Prism in Frame system. Compatible With Trimble GEDO Prism in Frame 4 520 101 Other compatible Trimble GEDO prism setups us ing a 5/8" thread