Abstract: A telescope with a foldable and extendable base that can be extended before use and folded after use, including a telescope main body being cradled in a socket; a stanchion having an upper joint connecting to a joint base of the socket; a left base having a ring with an arc external cover and a left leg on a lateral; a right base having a circular groove with an arc body and a right leg on a lateral; a sliding base having an upper hinge for connecting with a lower joint of the stanchion through a bolt and a nut; a bolt passing through the circular groove and the bolting hole of the sliding base to enable the sliding base sliding round the ring and the arc external cover sliding round the arc body.

Abstract: A device capable of exchanging image projection directions includes an inner body provided with an internal reflector having adjustable angles and a horizontal light permeation aperture; an accommodation tube formed at the rear of the inner body and an upper light permeation aperture formed at the top of the accommodation tube; an outer accommodation barrel disposed with at least two connection openings at the outer periphery thereof; and an inner accommodation barrel disposed with a long orifice and an outer connection opening, and is further flexibly connected into the outer accommodation barrel and fixed around the accommodation tube, such that the long orifice corresponds to the upper light permeation aperture for forming a path for light beams. The connection openings are connected to binocular connection barrels having various magnifications in advance, thereby viewing images with different magnifications and viewing ranges without dismantling or assembly of the binocular connection barrels.