The AFB is a versatile design which uses two pieces of stiff material, hinged on the frenum side of the penis and secured on the dorsal (top) side by an adjustable mechanism to hold the pieces firmly enough that tension can be applied. Closure options include a machine bolt and wing nut, velcro strip, and a string with beads.
Flattened PVC electrical conduit
1/2" (12.7 mm) wooden dowel wrapped with rubber from bicycle inner tube
A wooden rule, string and beads
PVC (plastic) electrical conduit - 7/8" O.D., 5/8" I.D.; sold in 8-foot lengths
2 feet of cord (boot lace or similar)
1 - S-hook
2 - 4" machine screws with wing nuts
1 Cut 2 pieces of PVC ~5" (12.5 cm) long. Immerse in boiling water for about five minutes. Remove from water and immediately flatten by placing a board on top and applying weight (you can always reheat them and do again if necessary.)
2 Drill holes as shown. Use drill or Dremel tool to turn one hole into a notch.
3 Tie loop of string through holes.
4 Add the closure device - bead with strings works fine, but you might prefer a bolt with wing nut - and you're ready to go!