Scoutmaster’s Equipment Tips
Backpacks
Backpacks come as two types.  They’re either external or internal frames.  Personal preference drives your choice as either is excellent. 
It’s recommended that you wait until your Scout is at least 14 before purchasing a backpack.  This is because your son is still growing and you want a backpack that fits well.  If possible, use the Troop’s backpacks or borrow while your son grows.
External Frame
Internal Frame
Backpacks
There are two basic types of backpack.  Internal and External Frame.  Each is recommended, so it comes down to personal choice.

If at all possible, don’t purchase a backpack for your son until they’re at least 14.  Your son will put in a lot of growth in their first few years in the Troop.  Any backpack purchased prior to 14 will most likely be too small when they’re older.  Like a good pair of hiking shoes, a well fitting backpack is critical.

For a good backpack fit, visit several stores and try their packs on.  Also, use the experience of the sales staff.  Your Troop Leaders are also good resources and can introduce your Scout to their various choices.