There are 2 types of inserts for v4 GR. These inserts are the close ended inserts that's designed for the end post and middle post. If you are looking for the divider post in the middle of a section, you will need to use: https://fencerail.com/products/guardrail-v4-circular-plastic-insert-for-support-divider-post-1pc --------- 36" Height Section needs 12x Plastic Inserts 42" Height Section needs 16x Plastic Inserts ------ 36" Height End Post needs 6x Plastic Inserts 42" Height End Post needs 8x Plastic Inserts Why replacement parts cost more: Our full kits are strategically positioned across warehouses throughout the country, which keeps logistics costs low. Replacement parts don't move in that volume — we have to specially track, ship, and manage them individually. That drives up warehouse fees, inbound and outbound handling, freight, and postage cost per unit.