diff --git a/Ploopy-Trackball-Kit-Assembly.md b/Ploopy-Trackball-Kit-Assembly.md
index dc8ffc0..86f5939 100644
--- a/Ploopy-Trackball-Kit-Assembly.md
+++ b/Ploopy-Trackball-Kit-Assembly.md
@@ -139,6 +139,10 @@ Prepare the following components:
 ## Step 20: Insert dowels into scroll wheel
 ![](https://lh3.googleusercontent.com/5EwI-F1MXSFo3l0OZtish4yHCMQTsYw6ilrF88hUlbgarZiQzROBkEH4uISmkKLQni1kas5bkRtpjD0WF0OZBwlyzBoo2zwVDMvU_DmMtHcnBNYoz0mMLLwgqu9vRg87MXKDqYbN_5hJGrXNDEwDOA4IIDcEJ7FUOogq4PNLXcKZ9hGeN4xjQFsKu8RvCBBxIcFbAYRrTVs-M2PUR5QsVo1cDrrNSwM3mziZ_DlB65D7TlTpfLNbbVUDLBQn9_pHztRe-9717Li3xc016Z3eY5mkYXMojsJes9ch2bcPgWQDuvEAXYBj_YukTJRGVfQ69U4daNSXKDmKO-CnqGspzxl6gCdQRVTppmJVQw5mP-dpW9_S9NN0r3_phggbcqi1otlJ82cTDGA3bHf2qvxh4NVqVJkEa05S7iDW4fHwtql8E05O29_TePBoMV2Xg7N2bX6j6ul6dVpqI23qmz4AIyRMBKhSHJSNUEcfCrx03pZvE5_-05m2ci86JRMAwS2zN5DxSNL6BHJq9O1JI2xHxZ20MtOBzYnN27y5PQe4_6a4d0OTRmZdCGL-9CpkoCw1iQhdiBEtIwagre4L_07V3WB7SUmvV9wq8SujnA5AEJQ2TeLW4qcUpUrU-TzAb2NvxoxK40nmoTIz_qlXzqVjvu2Hisa-zYAcXbXlcfzUadQ7rNhov4j2ajcnzXPdYODJeK-0TtsFWqvfshk2P4Bxy-bGwwWvcYVUEH3OngDpUNikSCU=w1454-h969-no)
 
+- You will likely require a hammer to push the pin into the scroll wheel. If you don't need one, consider yourself lucky.
+- The pin on the flat side of the scroll wheel will stick out 10.4mm when the pin is fully inserted.
+- The pin on the other side of the scroll wheel will stuck out 13.6mm when the pin is fully inserted.
+
 This might require some force, but it's probably doable without a hammer.
 
 ## Step 21: Thread silicone ring onto scroll wheel