High imitation substitutes. The United States imports filter paper
AAF Pulstar inlet systems require one of two filter arrangements: 1) When the system uses vertically- mounted filters, choose the 34.5"-long replacement filter, as shown below. 2) When filters are installed horizontally in a 'crossflow' system, pair two filters to obtain the required 56.5" total length, as shown at right.To obtain the 56.5" length,
use a 34.5"filter with a 22"-long filter,
or two28.25"-long filters. Both arrangements provide the same operating characteristics, but the 28.25" filters cost less and are easier to handle & install.