Here is a visual aid if the 3D CAD Model isn’t listed on the product page. For example B10B-PH-K-S(LF)(SN). Go to the supplier site JST — World Class Quality Interconnection Products.
Enter in the part number without the lead-free tin plating suffix’s “(LF)(SN)”.
Click on any of the series
Then scroll down the product page and click on the download under 3D Data.
