SAWSTOP RT-PZR - 4 pc Phenolic zero-clearance Insert Ring Set for Router LiftSolid phenolic inserts that can be cut to deliver exact results for each of your favorite bits. Actual dimensions: 3 3 4 w, 3 3 4 d, 1 1 4 h. Ultra strong phenolic core material to reduce tear out and chip out. Features Ultra strong phenolic core material to reduce tear out and chip out Four point, cam style lock to ensure a secure lockdown Machined to precisely fit the SawStop RT LFT Router Lift