XTAR VP1 Charger Kit - Have been using two of these units on a daily basis with 18350, 18500 & 18650 AW IMR, also with Samsung flat-top 18650's. Have not needed any spacers to charge the 18350's. I strongly advise reading the downloadable manufacturers instructions, especially the section on selecting the amp charging rates for different battery sizes. The unit has to be powered before inserting the battery(s) in order for the charger to read the current battery status. I especially rate the soft-start process & the facility to view the progress of each independent charging channel. Both the batteries being charged & the Xtar unit remain cool throughout the charging process. Obviously you can charge different battery sizes at the same time. There's a lot of very good reviews on the web relating to the technical competence of this unit - also the sound re-assurance of purchasing from Cloud9. I personally rate these units highly, good value reliable charger from a reputable manufacturer.