This miniature supercharger is great for boosting small engines and it can also be used as an air turbine. The model is 6centimeters wide and the shaft is 8 milimeters in diameter. The supercharger can be printed with plastic bearings, however these will not withstand as high of speeds so I will add a link for the bearings that meet this models specs: https://www.amazon.com/YONETRIX-Bearing-8x22x7mm-Miniature-Bearings/dp/B0FH6QH8VQ/ref=sr_1_1_sspa?adgrpid=186996563908&dib=eyJ2IjoiMSJ9.ANDE91GR-bYdpE6Ku1rcHCi1FrJydSBZ_v0s2f1oPVwQoWpwzfrguAe_h6dm7MO1_2pM8YXZMY82SS1Quhm11p0GgIWiJi7u8-nHOZS-_MftgEg39oAqPt1iirS-tKA7rVsKKNNDAIjKZZJezYVMHwo7umi5mtABcAfeQPajwCcom0CQcRs5aqimyOBzVa3HsvXJUNJl0Ahv8IuGrVkGYJJXGm4inUhicYogqc1HNc8.n9VJl2rBC7puaBkA4_6KgW6CDExjutv4xKhRJfzL3gE&dib_tag=se&hvadid=748008509454&hvcampaign=dsadesk&hvdev=c&hvexpln=m-dsad&hvlocphy=9010281&hvnetw=g&hvocijid=9178752940187316235--&hvrand=9178752940187316235&hvsb=Vehicle_ReplacementParts_d&hvtargid=dsa-2416893513815&keywords=bearings&qid=1766503128&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1