4PF = 4 RC functions uses battery box 64228 uses SBrick but of course works with Lego IR
RC functions: * driving, left and right are separate functions (each XL) * raising-lowering front blade (medium) * raising-lowering rear diggers (medium)
non-RC functions: * cabin can be opened to switch the battery box.
problems: * traction only works at carpet and alike (tracks' regular problem) * rear digger should not be lowered to max otherwise will mess up with drive. not necessary as digger can go 2 studs lower than the bulldozer anyway without maxed. * front blade also lowers lower than bulldozer itself (realistic) but it can cause problems on driving at carpet etc. test on sand and it will work fine.