Puzzler Novice / Challenge / Avenger
a.k.a. Turnstile, Twinspin, Engels Engima
Patented by D. A. Engel 1983, copyright GO Images Inc. 1986.
(plastic with cover, 4.75 by 6.4 by 1/2 inch;
the photos above show the puzzle on top of the cover)
The directions below are on the back of each puzzle;
Douglas Engels Solution Book,
from: www.uspto.gov - patent no. 4,415,158