Chuck and Hal Chandler
For some reason, Hal decided to stopped summoning Chuck thus leaving him trapped int another dimension. Hal married Peggy Clark and had two characters. Bruce Banner once stole the glasses and summoned Hal when he feared the Hulk would emerge. 3-D Man was among the heroes summoned by the Grandmaster.
Delroy Garrett Jr.
Hal could summon 3-D Man while concentrating and wearing the special glasses. When 3-D Man was active, Hal would be comatosed. 3-D Man could only exist in our world for three hours. When not summoned, he existed in the second dimension.
3-D Man's mind is a synthesis of Chuck and Hal's consciounnesses. 3-D Man wore an alter NASA flight suit that was bonded to his skin. 3-D Man has three times the pyshical abilities and senses of a normal "extremely ... fit" (Wikipedia) human. He also had the ability to sense Skrulls. Delroy gained these powers, but didn't need to be summoned.
Chuck was a talented foorball player and expert pilot. Hal is a skilled scientific researcher. However, he needed glasses and crutches (the latter due to poliomyelitis).