Walk Behind Spiker, Let Nutrients Into Your Lawn With Our Do-It-Yourself Spiker Aerator, Spike Aerators Use A Series Of Rotating Star-Shaped Tines That Slice Into The Soil To Allow Seed, Fertilizer, Water, Air, Light & Nutrients To Reach The Grass Roots. Aerating Should Be Done When The Lawns Moisture Content Is High. Some Assembly Required, Aerator Type: Push/Pull.