Shop › SANTAN STT-15 PILLAR UPPER RECEIVER SANTAN STT-15 PILLAR UPPER RECEIVER $206.50 San Tan Tactical STT-15, Upper, 223 Rem, 556NATO, Black, FT STT-PILLAR-1 Quantity: Add To Cart Added! San Tan Tactical STT-15, Upper, 223 Rem, 556NATO, Black, FT STT-PILLAR-1