Battery holder for 8 AA batteries = 12V Confirmed to fit: KO Propo EX-I Futaba Magnum Racer (FP-T2PKFA) See here: youtu.be/rhri3Op0Kgk Also confirmed to fit: KO Propo EX-I PRECIOUS KO Propo EX-I Mars KO Propo EX-I UR KO Propo EX-2 EX-II KO Propo EX-7 KO Propo EX-9 KO Propo EX-10 HELIOS KO Propo EX-10 EURUS Futaba Magnum PCM (FP-T3PG-X) Futaba Megatech PCM (FP-T3PB) Tamiya Adspec Sanwa DASH-S (box separate type) JR Propo BEAT202 JR Propo XS3 Although unconfirmed, it seems usable with the following models: Futaba FF7 FP-T7UAP FP-T7UAF Futaba FF5 FP-T5UAP FP-T5UAF Futaba FF3 FP-T3UCP Futaba Megatech FM KO Propo EX-3 KO Propo EX-5 KO Propo EX-5 MASTER KO Propo EX-5 UR KO Propo EX-10 KO Propo EX-11 PRESTO JR Propo MAX series JR Propo BEAT2 JR Propo X-347 JR Propo X-756 JR Propo X-3810 JR Propo X-388S JR Propo R-756 Kyosho PERFEX KT-5 Packaging will be "product directly in an envelope" (due to the thickness being barely under 3cm). Thank you. *If you need multiple items, please consult in the comment section before purchasing. We will accommodate at an additional 420 yen per item.