No, it is not required. However, not all 3rd party coupling products are compatible with the M201 meter.

Use of a spacer tube is strongly recommended for all new plumbing installations. Debris that often gets in the water supply lines during installation can easily become lodged in a water meter's flow chamber, preventing it from incrementing.

Using a spacer tube allows the lines to first be flushed to ensure the water meter works correctly once it has been installed.

Yes, the ST201 Spacer Tube works as a temporary spacing tube for standard 7.5" long meters.