Current EL and QEL baseplate conversion kits can be used on all latching types of the 33/35 series (non "A" version which were manufactured prior to 2003).  At one time, the obsolete black EL potted module caused too strong of a pull for the 33/35 rim device, but today's amber colored EL potted module is not a problem.  Note: the baseplate conversion kits are not compatible with 33/35 devices manufactured prior to the mid-1980s.  Those baseplates have an easily identifiable appearance which differs from the current baseplate. Refer to the device parts manual for images of the current baseplate.