There are the following choices:

• Cumulative Totalling – Each handling rate found is totaled together to get a final rate that is added to the shipping cost.  So, for example if I had Product A with handling rate $4 per order, and Product B with handling rate of $5 per order the final handling rate would be $9
• Highest Price Totalling – Handling rate is ascertained by the highest rate across the groups. So using above example handling rate would be $5
• Per Unique Product Totalling – Handling rate is calculated per unique product in the cart. E.g. Product A (qty = 100) + Product B (qty=50) the extension would see the quantity as 2
• Per Item Totalling – Handling rate calculated based on each item’s individual price.  E.g. If I have 2*BIKES which have price of $50 each would match on a price filter rule of 0-80, but not on 80-120 as looking at each individual price ($50)