Maybe the SupBeam K40, aka clone of the TN31. There are some differences for sure. Ie smaller reflector(69.3mm K40 v 69.5mm TN31 and 52mm deep K40 v 64mm deep TN31, driven to 3Amps, although Jake, vendor here has version that is driven to 3.5Amps current. This could be less expensive option for some who would like a 90% modded TN31. These lights should retail for about $90.00 for the 3A version or $120.00 for the 3.5A one. Personally, I'm willing to pay the extra for the best and if the TN31 is better quality then that's ok. But occasionally there are easter eggs in these less expensive lights in that they may be easier to work with or something. See the two versions Supbeam dot com or the other K40 in the dealers area of the marketplace.