AUDUBON, PENN. — NKF Capital Markets has brokered the $20 million sale of a 136,918-square-foot office building in Audubon. Located at 1001 Adams Ave., the property is currently fully occupied by Optum 360, a UnitedHealth Company. Amenities at the property include a full-service cafeteria, on-site fitness center with showers, outside patio dining and video conferencing facilities. Mike Margolis, Dave Dolan, Dave Garonzik and Jeff Mack of NKF Capital Markets represented the seller, Delaware Valley Real Estate Investment Fund, in the transaction. The buyer was Blue Stone Capital.