The shooting rest rest bag comes in two pieces - which can be clipped together to make sure you dont lose them. They do need filling - eg use sand, polystyrene, rice or cat litter (unused recommended)
You can use these to rest your shotgun / rifle / air rifle on when not shooting - so you dont scratch it / knock the scope, or get it dirty. If you want, use the front bag to rest the gun on whilst shooting.
The approximate sizes when filled are: Front: 22cm wide, 10cm deep, height 18cm / 14cm. Rear: 9cm wide, 6.5cm deep, height 10cm / 5cm