Here are Hornby R8239 Digital Booster and R8238 Digital Reverse Loop Module. Both have never been used, just the box opened.
Hornby R8239 Digital DCC Booster. Unused but missing original manual
Littfinski Ldt 080063 - Digital Booster DCC Z21 R8239 DCS100 5301 ZTC550 36520
Hornby R8239 DCC Power/Signal Booster
HORNBY R8239 BOOSTER UNIT FOR DCC LAYOUTS BOXED APPEARS UNUSED
Boxed Hornby R8239 DCC Power Signal Booster OO Gauge
Decoderwerk 00101 Digital Booster 5A Adjustable Short Circuit Time + Current