54-199-105-0 Fowler-Trimos 4mm Probe Set, FREE ShippingFor use with Fowler Trimos Height Gages. Complete Probe Kit includes Disc Shaped Insert: 7. 7mm Disc Shaped Insert: 11. 5mm Corner Insert 1mm Measuring Insert Holder for: M2. 5, M1. 6, M1. 4 Insert Holder: L=80mm, M2. 5 Insert Holder: 90 L=80, M2. 5 Ruby Ball Probe 2mm Ball Probe 1mm Knife Edged Measuring Probe L=88mm Holder with Reduction 8mm 4mm Swivel Holder: 4 8mm Hemispheric Probe Probe with Pin (plus 4 additional pins) Test Indicator Tip: 1mm