4" Regulation Golf Cup - Bright White Aluminun Practice Putting Green Cup for Natural or Synthetic Greens Durable Bright White Cycolac & Regulation 4" Aluminium Cups feature minimum taper for a snug fit. Used On Golf Greens World Wide! Same ones that are include with every synthetic putting green kit. Put one in your lawn and be the envy of your golfing buddies! Your own practice putting green! Also available in 4" & 6" Bright White Plastic & 6" Regulation Aluminum on Amazon.com