In other words

Aerates Ponds/Lakes Where No Electricity Is Available - Up to 3 acres and 25' deep

diffusers performing at an optimal level above the pond bottom

RA systems 4-6 do not include airline allowing for the customer to order only what they need or require

Pole-mount enclosure

Airmax RP50-87R 1/2 HP Compressor Rebuild Kit Beneficial Pond Bacteria In other wordsAirmax SilentAir RP Series Maintenance Kits contain the parts you need to restore your Airmax Aeration System to its maximum potential. Maintenance Kits should typically be installed every 12 to 18 months to ensure optimum performance. These maintenance kits are designed to be used in the following: Shallow Water HP Series, PondSeries and LakeSeries Aeration Systems. Please note that the 87R designation means this rebuild kit is intended to be used