TROMBONE LEVELING BLOCKDesigned for aligning both inner and outer slide pipes, our #2076 Leveling Block is constructed using heavy plate glass enclosed in a wood case. Two steel riser blocks machined perfectly flat set on either end of the glass. Slide pipes are set on the riser blocks to determine skew or twist. Works great for soldering and reassemby work. When soldering, simply position the area receiving the heat off of either end of the block. To help hold pipes in