Procom DPF 2/44...

The DPF 2/44… is a 8-cavity duplex filter for duplex radio transceivers.
This duplexer is delivered in a low band version type DPF 2/44 L, tunable within 138 - 156 MHz and a high band version type DPF 2/44 H, tunable within 152 - 175 MHz. These models are again delivered in 3 submodels, each dedicated to work with a certain duplex spacing. See “Ordering information” below.
The DPF 2/44… models are primarily intended for equipment, where the TX and RX operate on several channels, i.e. within a certain port bandwidth.
The filter has very small physical dimensions owing to the use of high-Q, temperature compensated helical resonators.
The housing is made of extruded aluminium, the chassis of passivated steel, and teflon insulation has been applied in the rigid coaxial cables and in the connectors.
The filter is black vinyl-coated to prevent corrosion.