A tape measure comprises a housing having a bottom surface and a front surface substantially perpendicular to the bottom surface so that an opening is formed through a lower part of the front surface, a measuring tape strip elastically wound within the housing to become externally released through the opening. In some embodiments, a method of packaging a semiconductor device includes forming a mask coating over a carrier, coupling an integrated circuit die over the mask coating, and disposing a molding compound around the integrated circuit die. Measurement-variance estimates generated from the SNR are provided to a target-state estimator when the target is determined to be a point target. The shaft coupling guard further includes a leg portion formed integrally with the guard main body and configured to support the guard main body. At least one lift pin is used for supporting the substrate relative to the support layer.