9.25x12.25” with stiff paper covers with 50 slick paper pages printed on one side. Extensively illustrated with art and photos of riders in many activities including touring, hunting, fishing, hill climbing and delivery. Most pages promote “80 Miles Per Gallon” efficiency. Undated but Harley Single was only made between 1917 and 1927. Catalogue has moderate to heavy aging with scattered moisture marks here and there and numerous handling creases, most noticeable on front and back covers. One page near front of catalogue has surface paper lift at corner. Overall Good/VG. A wonderful early Harley reference.