Pro-Style Double First and Two Standard Bases is constructed of a one-piece rubber mold so bases will not separate. Bases compress upon impact. Aluminum stanchion fits a male or female ground anchor. Double anchoring system. Double first base reduces the chance of collision at first base. One-piece, Heavy-gauge, rigid all-rubber construction. Includes universal aluminum stanchion fitting both 1" and 1 1/2" anchors.