For over 60 years, SPI has introduced innovative products to the metalworking and laboratory industries. SPI measuring instruments are durable, precise, and reliable — all backed by an industry-leading 2-year warranty. SPI 20-841-3 Indicator Positioner Vertical Arm: 2 inch High, for 5/32" Stems. Allows quick and accurate adjustment of indicators; 2 inch high vertical arm is for setups with plenty of clearance; 2 inch vertical arm provides better visibility of the indicator for 5/32 inch stems.