Click above image to watch the promo (1MB)
During Sliders season three, Fox had a network-wide promotion where the stars of the various shows would introduce their programs with 5 second segments saying "You're watching Fox". While the Sliders promo was rarely seen (and in some locations never seen), it did exist. The only known time that the promo introduced a Sliders episode was the episode "Double Cross." According to all other info I've found, the only other times the Sliders promo appeared were randomly during other Fox programming.