These custom riser blocks come in two heights to raise our CRC fly rod carrier 1.5 inches, or 3 inches, and are sold in a set of two. Riser blocks also come in two lengths. The 4 inch length riser blocks will fit Trxstle's 2-rod carrier. The 12 inch length riser blocks will accommodate a 4-rod capacity setup (2 carriers). Riser blocks are compatible with our CRC Fly Rod Carrier T-Track mounts. MADE TO ORDER - ALLOW UP TO 2 WEEKS BEFORE SHIPMENT Customers must provide their own rack hardware to attach the riser blocks to their roof rack - check with the rack manufacturer if you are unsure of what hardware you need. Adds 1.5" or 3" of clearance under the CRC System All sales of custom-built rack products are final and non-returnable. Due to the fabricated, made-to-order nature of these items—engineered specifically for individual vehicles and configurations—they cannot be resold or repurposed.