Special cases made to specifications of the USGS, with additional utility and service features. Inside divider is special shape molded to give 1/4″ thickness capacity next to back panel.
Inside dimensions of book pouch is 8 1/2″ x 5 3/4″ x 3/4″ for DI-6 and similar size books.
Front panel has 3 pencil loops (two loops are 3/8” diameter and one is ½” diameter) and 2 scale pockets for boxwood or C-thru. Loops and scale pockets are heavy calfskin with double stitching along the outside edges and rivets on lower corners.
Flap is secured with Lift-the-Dot fastener, for positive locking. Not adjustable for longer books.