Bristol has announced its new Benchmark H21J reciprocating compressor, requiring no starting components, improving reliability, and boosting the SEER rating. Benchmark divides its product line between the H21J Recip-which is unmatched in performance and efficiency for applications below 3.5 tons-and the Benchmark Scroll, which is superior in larger applications. Every Benchmark, recip or scroll, is noticeably quieter than the leading scroll. Bristol Compressors.