Check the listing for details. RAP-421 RAM Dual T-Bolt Track Base for Spline Posts.... Color: Black, Condition: New. Listed at 26.94 USD. RAM Dual T-Bolt Track Base for Spline Posts... RAP-421 Genuine RAM Products! The RAM Track Base for Spline Posts is a rugged track mount solution that's also ideally suited for use when you're out on the water. If you're using the Track Base to mount a rod holder while trolling, it's a great choice as the Track Base won't loosen. Compatible with the RAM Tough-Track, it features two knobs and a hole that allows for the attachment of any RAM Spline Post.hardware included (2) 1/4 INCHES -20 x 7/8 INCHES T-Bolts(2) 1/4 INCHES -20 Knobst bolt dimensions .48 INCHES x .95 INCHES hole pattern 3.5 INCHES materials High strength compositepackaging type Retail BagWeight 0.35 lb hardware included (2) 1/4 INCHES -20 x 7/8 INCHES T-Bolts(2) 1/4 INCHES -20 Knobs t bolt dimensions .48 INCHES x .95 INCHES hole pattern 3.5 INCHES materials High strength composite packaging type Retail Bag Weight 0.35 lb