This is the Top Shootbolt section of the Sentinel XP25 Swing Multipoint Lock
This part, the 450 Top Shootbolt is 1 of 3 pieces of the multipoint lock
This Top Extension When used with 36 inch handle height is for a 93 inch tall door

Extension Width: 25/32 inch (20mm)
Overall Length: 34-15/32 / 34.468 inches (875mm) Shootbolt retracted
Shootbolt Tip: 450 Standard Series
Material: Stainless Steel

Note: The bottom / Lower extension is the same as the Upper, Handle height can be changed by using different length extensions.

How to Rehand an Ashland Multipoint Lock (Marvin Doors)
 

 
Rehanding Ashland Multipoint Locks