When orders are synced with SKULabs, the quantities of the items needed to fulfill those orders are automatically reserved from their on hand count. Reserve quantities are released once an order is fulfilled and marked as shipped.
The reserve quantity for an item can be seen in the Reserved row, under the Stock panel in an item's details page.
In this example, the number of Purple Spoon's currently being reserved by orders is 10.
The Past Orders Panel
Further down the item details page, the Past Orders panel allows you to quickly see specifically which orders are reserving stock from this item and how much.
You can change how many orders are displayed with the "Show __ entries" option on the top left:
You can also sort this table using a range of dates and further sort by orders currently reserving stock by clicking on the "Reserved" column header on the far right until the arrow beside it is pointing downwards.
Any orders currently reserving stock for the item are denoted by a check mark.
Orders not currently reserving stock for the item are denoted by an X icon.