The strength and volume of the compressor directly affect how long you can hold down the trigger
And though not shown in parts image at top of page it also includes:
Works with 1 1/2 HP and larger compressors
Reason being is the diaphragms are blank when new
Compressor recommendation :
Suction Set, Complete, Metal-Flex, (9140, 1420, XT250, XL255, PF23) New Ver. Option:Kit A The strength and volume of0516197 or 516197 This is the newest "S" shaped metal flex suction set for DPS Apex XT units that are on stands. (A "Stand" model has No wheels.) This S shaped metal flex suction set can also be used as an upgrade suction set on several older units. Designed for Wagner SprayTech Titan: 9140, 1420, XT250, PL800 Also compatible with Wagner SprayTech: 9135, PF23, 1400, 935, 841, 844, and more! Upgrades part numbers 0512215 & 0295182; direct replacement