Panasonic CF-20 Series Operating Instructions And Reference Manual page 133

3. Pass the belt which has the Velcro straps through the strap holes (C) located on the side of the back of the tablet.
4. Securely attach the bonded part of the belt so it does not loosen.
Insert the tip of belt into the cut hole of the hand strap.
5. <Only for model with the tether> Attaching the tether to the hand strap.
1. Pass one of the loops through the hole.
2. Pass one of the loops through another loop.