diff --git a/SOPHIE-Alignment.md b/SOPHIE-Alignment.md
index 207384d..1b5c361 100644
--- a/SOPHIE-Alignment.md
+++ b/SOPHIE-Alignment.md
@@ -40,7 +40,7 @@ In this design the virtual drift is determined by the long reference mirrors in
 
 | ![Ref_Mirror_combi_view](uploads/d38a778a85914474d4493113f1d3fd23/Ref_Mirror_combi_view.jpg) |
 |:--:|
-| Figure 3. Design drawings and 3D render of the reference mirrors. |
+| Figure 3. Design drawings and 3D render of the reference mirrors. The [alignment screws](https://www.thorlabs.com/thorproduct.cfm?partnumber=P25SB100V) ([P25SB100V](uploads/48b6c202c417e8f890c64728ddda7d4a/P25SB100V-AutoCADPDF.pdf)) have a thread of 1/4''-100 and so each full turn will change the local mirror height by XX.  |
 
 
 ## Fixing the SOPHIE Alignment