Testosterone Has Rewarding Affective Properties in Male Rats: Implications for the Biological Basis of Sexual Motivation (Alexander 1994)
- The apparatus is made of colored Plexiglas, with a clear Plexiglas front wall.
 - It consisted of two conditioning compartments of identical size (41.5 cm x 41.5 cm x 38 cm) and a smaller, central connecting compartment (8 cm x 41.5 cm x 38 cm).
 - One conditioning compartment was white and had wood chips scattered on the floor.
 - The second conditioning compartment is black.
 - The central, connecting compartment is gray.
 - Central walls separating the connecting compartment from each conditioning compartment could be removed to create one large test chamber (91 cm x 41.5cm x 38cm).