ProCage^TM Dry Line Markers by Trigon Sports feature all steel buckets & steel axles. Lids feature a guide stripe for easy, straight application. Handle mounted control lever adjusts lines from 2" to 4".  The ProCage^TM  100lb Dry Line Marker comes complete with 4 pneumatic tires. Other models include the ProCage^TM 50lb Dry Line Marker & ProCage^TM 35lb Dry Line Marker.