Märklin H0 — 60933 mfx High-Efficiency Decoder with Sound Effects Generator — Electric Locomotive Upgrade Kit Factory-sealed example with the original Märklin seal intact. The box has never been opened and the contents have never been removed or handled. Close to mint condition with some light storage ageing to the outer box consistent with long-term collection storage. No longer in regular production — a sought-after digital upgrade set in original sealed box. Original Märklin mfx high-efficiency decoder and sound upgrade kit for H0 electric locomotives. Designed for converting Märklin H0 locomotives already fitted with high-efficiency propulsion (motor sets 6090, 60901, 60903, or 60904) to the newer mfx generation with load regulation feedback and integrated electric-loco sound. The existing high-efficiency motor remains in the locomotive; only the decoder is replaced and the included loudspeaker is installed. Product details: - Scale: H0 (1:87) - Type: mfx high-efficiency decoder with sound generator - For electric locomotives with Märklin high-efficiency motors 6090 / 60901 / 60903 / 60904 - Existing motor is retained; decoder is replaced and loudspeaker added - 12 pre-programmed electric locomotive sounds, including: - Basic electric running sounds - Relays clicking (F8) - Excess pressure safety valve releasing air (F11) - Door closing sounds (F14) - Conductor’s whistle (F15) - Direct control function without acceleration/braking delay available - 3 freely assignable function outputs, one direction-dependent (e.g. for headlights / marker lights) - Decoder PCB dimensions: approx. 35 × 15 × 6 mm - Speaker diameter: approx. 22 mm; height: approx. 3 mm - Compatible with Märklin Central Station, Mobile Station and other Märklin Digital controllers Photos are part of the description and reflect the condition of the item. Please review all photographs carefully. Only items visible in the images are included in this sale. Shipping: By courier service exclusively for fast, reliable, tracked delivery. International Buyers: Please note that the seller does not ship to the USA due to unpredictable customs clearance procedures. Bidders requiring USA delivery should not place bids. Listing Transparency: This product description was compiled with AI assistance to ensure accurate specifications and historical context. The seller encourages prospective bidders to independently validate all information before bidding.